Why Your PNG Has a White Background

You finished a clean pixel-art icon in Microsoft Paint, saved it as a PNG, and loaded it into the Unturned™ inventory. Instead of the icon floating cleanly on the inventory grid, it sits inside a glaring white rectangle. The icon is correct. The white rectangle is the problem. For 57 Studios™ contributors this is one of the most frequently reported issues from new modders. The cause is a limitation in classic Microsoft Paint, and there is a clear pipeline for working around it. This reference explains why the white background appears, which editors handle transparency correctly, and how to integrate transparency removal into your icon workflow.

The white-background problem is one of the highest-friction issues in the beginner pixel art workflow. The icon looks correct in Paint. The icon looks correct in the File Explorer thumbnail. The icon looks correct in the Windows Photos app. The icon only looks wrong when it appears in the actual destination (the Unturned inventory, a Workshop preview, a website mock-up against a dark background). This reference walks through why the problem appears, why it is not detectable in many viewing contexts, and how to integrate a transparency-removal step into the standard workflow so that the problem never reaches the destination.

Prerequisites

• A PNG icon saved from Microsoft Paint.
• An understanding of what transparency means in a PNG.
• (Optional) An installed copy of GIMP, Paint.NET, or Photoshop for the recommended workaround.
• Familiarity with the Pencil tool, since clean transparency removal depends on hard pixel edges. (See How to Use the Pencil Tool.)
• A correctly sized canvas. (See How to Set Canvas Size for Icons.)
• A correctly saved PNG file. (See How to Save a PNG File in Paint.)

What you'll learn

• Why Paint's saved PNGs have an opaque white background.
• The difference between transparency in the saved file and transparency in the editor's preview.
• Workarounds: external removal in another editor, or designing over the destination background.
• A comparison of editors and their transparency support.
• The full icon authoring pipeline with the transparency step highlighted.
• How to verify transparency was correctly applied.
• How to handle anti-aliased edges and other transparency-related edge cases.

Background

A PNG image has up to four channels per pixel: Red, Green, Blue, and Alpha. The Alpha channel stores transparency. An alpha value of 0 means fully transparent. An alpha value of 255 means fully opaque. Anything in between is partial transparency.

Classic Microsoft Paint (the version included with Windows XP, 7, 8, and the original Windows 10 build) does not write an Alpha channel. Every pixel in a Paint-saved PNG has implicit full opacity, including the pixels you intended to leave blank. Those blank pixels are filled with the canvas background color, which is white by default.

Modern Paint partially fixes this

The Windows 11 rebuild of Paint, released in 2023, introduced support for transparent canvases and layered editing. If your Windows 11 Paint installation includes the "Background removal" or "Transparent canvas" toggle in the Image group, you have access to limited transparency support. Older versions and most managed-IT installations do not have this.

The four-channel pixel model

To understand why the white background appears, it helps to understand how a pixel is represented in a PNG file.

A pixel in an RGB (24-bit) PNG has three values: Red (0-255), Green (0-255), Blue (0-255). The combination of the three values produces approximately 16.7 million possible colors.

A pixel in an RGBA (32-bit) PNG has four values: Red, Green, Blue, and Alpha (0-255). The Alpha channel adds the per-pixel transparency information. An alpha of 0 means the pixel is fully transparent (the underlying surface shows through completely). An alpha of 255 means the pixel is fully opaque (the underlying surface is completely hidden). Intermediate values blend the pixel with the underlying surface.

Microsoft Paint saves PNG files in RGB (24-bit) format, not RGBA (32-bit). The absence of the Alpha channel means every pixel is implicitly fully opaque. The pixels that you left blank during authoring (the white background around your icon) are saved as fully opaque white pixels.

When the saved PNG is loaded by a viewer that expects transparency, the viewer cannot infer "these white pixels should be transparent." The viewer renders the white pixels as opaque white, exactly as the file specifies.

Pixel format	Channels	Bits per pixel	Transparency support
Grayscale	1 (intensity)	8	No
Grayscale + Alpha	2 (intensity, alpha)	16	Yes
RGB	3 (red, green, blue)	24	No
RGBA	4 (red, green, blue, alpha)	32	Yes
Paletted	1 index + palette	8	Single transparent color via tRNS chunk

Paint writes RGB format exclusively. The other formats are not available through the Paint save dialog.

Why the white appears

The chain of events:

1. You open Paint. The canvas defaults to white because the default Color 2 is white.
2. You draw your icon. The pixels you touch take on your chosen colors. The pixels you do not touch remain white.
3. You save as PNG. Paint writes RGB values for every pixel, including the untouched white ones.
4. The game (or any viewer) loads the PNG. Every white pixel is rendered as opaque white. There is no Alpha channel signaling "this should be transparent."

The white pixels are not a bug. They are exactly what you authored, even though you did not intend them.

Why this is not caught earlier

The white background problem is not noticeable in many viewing contexts because the contexts themselves use a white background.

Viewing context	Background color	White-pixel detectable?
Microsoft Paint window	White	No, indistinguishable
Windows File Explorer thumbnail	White	No, indistinguishable
Windows Photos app	White	No, indistinguishable
Most web browsers (default)	White	No, indistinguishable
Unturned inventory grid	Gray	Yes, white rectangle visible
Workshop preview (dark theme)	Dark gray	Yes, white rectangle visible
Discord avatar	Dark gray	Yes, white rectangle visible
Photoshop with checkered transparency overlay	Checkered	Yes, white opaque visible

The mismatch between "viewing contexts where the problem is hidden" and "destination contexts where the problem is visible" is the principal reason new modders are surprised by the white background. The modder confirms the icon looks correct in Paint, confirms it looks correct in the File Explorer thumbnail, and only discovers the problem when the asset reaches the actual destination.

Workaround 1: Remove transparency in an external editor

The most common solution. Author the icon in Paint, then run it through an editor that supports alpha output.

Using GIMP

GIMP is a free, open-source raster editor that fully supports PNG transparency.

1. Open the Paint-saved PNG in GIMP.
2. Right-click the image, choose Layer → Transparency → Add Alpha Channel.
3. Use Select → By Color and click any white pixel. All white pixels are selected.
4. Press Delete. The selected white pixels become transparent (shown as a checkerboard pattern).
5. File → Export As → PNG. Save with the same filename, replacing the original.

Using Paint.NET

Paint.NET is a free editor designed as a more capable Paint successor. It supports transparency natively.

1. Open the Paint-saved PNG in Paint.NET.
2. Use the Magic Wand tool with a low tolerance setting to select the white background.
3. Press Delete. Transparent pixels appear as a checkerboard.
4. File → Save As and overwrite the original.

Using Photoshop

Photoshop offers multiple removal techniques: Magic Wand, Quick Selection, the Select Subject command, or the Remove Background feature in modern versions.

1. Open the PNG.
2. Use Quick Selection to select the icon.
3. Select → Inverse to invert.
4. Press Delete.
5. File → Export → Quick Export as PNG.

Using Krita

Krita is a free editor focused on digital painting. It supports transparency natively.

1. Open the PNG in Krita.
2. Use Select → Color Range to select all white pixels.
3. Press Delete to clear the selection to transparency.
4. File → Export to save the modified PNG with the transparency intact.

Using Aseprite

Aseprite is a paid editor focused specifically on pixel art. It supports transparency natively and has dedicated pixel-art tools.

1. Open the PNG in Aseprite.
2. The white pixels are imported as opaque pixels in the bottom layer.
3. Use the Magic Wand tool to select all white pixels (set tolerance to 0 for exact match).
4. Press Delete to clear the selection to transparency.
5. File → Export Sprite Sheet or File → Save As to write the file with transparency.

Workaround 2: Design over the destination background

If you know the exact color of the surface the icon will be displayed against (for example, the medium gray of the Unturned inventory grid), you can avoid the transparency problem entirely by painting that color into the icon's background.

Steps

1. Note the destination background color. For Unturned inventory, this is typically a neutral gray.
2. In Paint, before drawing, use the Fill bucket to flood the canvas with the destination color.
3. Draw the icon on top of the colored background.
4. Save and use the icon directly.

Limited to a single surface

This workaround only works when the icon is displayed on one known surface. If the same icon appears on multiple surfaces with different colors (inventory grid vs trader catalog vs Workshop preview), the painted background will look incorrect on at least one of them. Workaround 1 is more robust.

When this workaround is acceptable

The destination-color workaround is acceptable in the following situations:

1. Single-context icons. The icon will only ever appear in one destination (a fixed inventory cell, a specific HUD position). The destination color is stable across all rendering paths.
2. Prototyping. During early development, the destination-color approach lets the modder iterate quickly without setting up the transparency-removal pipeline.
3. Internal tooling. For mod development tools that only the modder will use, the visual mismatch on alternate backgrounds is acceptable.

In all other situations, the transparency-removal pipeline (Workaround 1) is preferred.

Comparison of editors and transparency

Editor	Saves transparent PNG	Reads transparent PNG	Cost
Microsoft Paint (classic)	No	Yes, but flattens to white	Free
Microsoft Paint (Windows 11 modern)	Limited	Yes	Free
Paint 3D	Yes	Yes	Free
GIMP	Yes	Yes	Free
Paint.NET	Yes	Yes	Free
Krita	Yes	Yes	Free
Adobe Photoshop	Yes	Yes	Paid
Affinity Photo	Yes	Yes	Paid
Aseprite	Yes	Yes	Paid
Pixaki (iPad)	Yes	Yes	Paid
Procreate (iPad)	Yes	Yes	Paid

Paint 3D also works

Paint 3D, the companion application shipped alongside classic Paint, does support transparent PNG output. The interface is different and less convenient for pixel work, but if you do not want to install a third-party editor, Paint 3D's Canvas → Transparent canvas toggle is sufficient.

Icon authoring pipeline

The recommended pipeline integrates Paint for drawing and a separate editor for transparency removal. The diagram below highlights the transparency step.

The three red-highlighted steps are the transparency stage. They sit between Paint and the asset bundle build.

Decision flowchart

Visualization: alpha values and visual effect

The visualization shows the relationship between alpha values and visual effect. Pixel art typically uses only two alpha values: 0 (transparent) and 255 (opaque). Intermediate alpha values (anti-aliased edges) are typical of photographic and brush-painted assets but undesirable in sharp pixel art.

Advanced considerations

Anti-aliased edges and transparency

When you remove a solid white background with a magic wand, any anti-aliased pixels along the edges of the icon may remain. These pixels are partially white and partially the icon color. The result is a faint white halo around the icon. The Pencil tool avoids this because Pencil strokes are not anti-aliased. If you used the Brush or imported a non-pixel-art reference, expect to clean up the edges manually.

The anti-aliasing problem is the principal reason the 57 Studios workflow recommends the Pencil tool exclusively for pixel art. Pencil strokes produce hard pixel edges; Brush strokes produce soft anti-aliased edges. The hard-edged Pencil output is straightforward to convert to transparency with a magic wand; the soft-edged Brush output requires manual cleanup.

Transparency in 8-bit GIF vs 8-bit PNG vs 32-bit PNG

PNG supports two transparency modes: single-color transparency (similar to GIF) and a full 8-bit alpha channel per pixel. For game icons, prefer 32-bit PNG with a full alpha channel. Editors default to this when you export from a layered or alpha-aware source.

Format	Transparency mode	Use case
GIF	Single transparent color	Legacy web, simple animations
8-bit PNG (paletted)	Single transparent color	Small file size, limited palette
8-bit PNG + tRNS chunk	Single transparent color	GIF-like transparency in PNG
24-bit PNG	No transparency	Default Paint output
32-bit PNG (RGBA)	Per-pixel alpha channel	Game icons, UI overlays

The 32-bit PNG with per-pixel alpha is the correct format for Unturned modding. The format is the default output of GIMP, Paint.NET, Photoshop, Krita, and Aseprite when transparency is present in the source.

Verifying transparency

Open the exported PNG in a viewer that displays a transparency checkerboard, such as the Windows Photos app or any of the recommended editors. If the background appears as a checkerboard, transparency is correct. If it appears as solid white, the alpha channel was not saved.

Additional verification methods:

1. Open in a web browser with a dark background. Create a small HTML file with a dark body background and an img tag pointing to the PNG. Open the file in a browser. If the icon floats over the dark background cleanly, transparency is correct.
2. Open in a text editor that shows file size. A transparent PNG has a meaningfully different file size than the original opaque PNG. The difference is typically 5 to 30 percent depending on the icon's complexity.
3. Open in Unity and import as a Sprite. Unity's import preview shows the transparency over a checkered pattern. If the preview shows white, the alpha channel is missing.

Premultiplied vs straight alpha

Some game engines expect premultiplied alpha (RGB values are pre-multiplied by alpha) rather than straight alpha. Unturned and Unity in general expect straight alpha. The free editors named above export straight alpha by default.

The distinction matters when an asset shows incorrect color blending at the edges of transparent regions. A premultiplied-alpha asset rendered in a straight-alpha pipeline will appear with darkened edges; a straight-alpha asset rendered in a premultiplied pipeline will appear with brightened edges. For Unturned mod work, straight alpha is correct and is the default output of the recommended editors.

Returning to Paint after transparency removal

Once a PNG has a transparent background, opening it again in classic Paint flattens it back to white. To preserve transparency through subsequent edits, stay in GIMP or Paint.NET for any further changes.

A safe round-trip workflow:

1. Author in Paint. Save with white background.
2. Remove white in GIMP or Paint.NET. Save with transparency.
3. For subsequent edits, open in GIMP or Paint.NET (not Paint). Edit with transparency preserved.
4. Save from GIMP or Paint.NET. Transparency is preserved.

Opening a transparent PNG in classic Paint at step 3 destroys the transparency by flattening the alpha channel to white. The discipline is to keep the transparent file out of classic Paint after the initial transparency removal.

FAQ

Why does the file look correct on my desktop but white in-game? Desktop file previews may render the icon against a white background by default. The game shows it against the inventory grid, which is a different color. If transparency is missing, the icon shows white anywhere it is rendered against a non-white surface.

Can I avoid this with Paint 3D? Yes. Paint 3D's transparent canvas toggle produces alpha-aware PNGs. The drawback is that Paint 3D's interface is less suited to pixel-precision work than classic Paint.

Will future versions of Paint fix this? The Windows 11 rebuild has added limited transparency support. If you have access to the modern Paint, look for Transparent canvas under the Image group or in Settings. The feature is gradually being expanded across Windows Update cycles.

Is there a Paint plugin that adds transparency? No. Classic Paint does not support plugins. Use GIMP, Paint.NET, or upgrade to modern Windows 11 Paint.

Does compression affect transparency? No. PNG compression is lossless. The alpha channel is preserved as exactly as RGB.

Why does Paint 3D's transparent canvas not work for my session? Paint 3D's transparent canvas toggle must be enabled before drawing. If the toggle is enabled mid-session, the existing canvas content remains opaque; only new strokes are aware of the transparent canvas.

How do I batch-remove white backgrounds from many PNGs at once? GIMP supports scripting via Script-Fu. A short Script-Fu script can iterate over a folder of PNGs, remove white backgrounds, and write transparent versions. The GIMP documentation includes example scripts for batch operations.

Why does my transparent PNG have a faint white halo around the icon? The halo is caused by anti-aliased edge pixels that are partially white and partially the icon color. When the magic wand removes only pure white, the partially-white edge pixels remain. Manual cleanup with the Pencil tool resolves the halo, or re-author the icon using only the Pencil tool to avoid anti-aliasing in the first place.

Can I add transparency to a JPEG? No. JPEG does not support transparency. To add transparency to an asset, save as PNG (or convert from JPEG to PNG first), then use the transparency-removal workflow.

Does Unturned support per-pixel alpha or only single-color transparency? Unturned supports full per-pixel alpha through its Unity asset bundle pipeline. The icons can have soft edges (intermediate alpha values), though pixel art typically uses only the two extremes (0 and 255).

How do I verify the saved PNG has an alpha channel without an editor? Right-click the PNG in Windows File Explorer, choose Properties, navigate to the Details tab. The "Bit depth" field shows 24 for an opaque RGB PNG or 32 for an alpha-aware RGBA PNG.

What happens if I save an alpha-aware PNG in classic Paint? Classic Paint flattens the alpha channel to white during the save. The output file is a 24-bit RGB PNG with the alpha-was information lost. Do not open a transparent PNG in classic Paint if you want to preserve transparency.

Best practices

• Adopt the Paint → GIMP/Paint.NET pipeline early. Doing so once during setup saves hours of corrections later.
• Verify transparency by opening saved PNGs in a checkerboard-aware viewer before considering an icon final.
• Use the Pencil exclusively. Anti-aliased edges produced by the Brush make magic-wand removal harder.
• Never rely on classic Paint alone for assets that require transparency.
• When in doubt, compare your output to a known-good icon in the same asset pack.
• Keep the transparent file out of classic Paint after the initial transparency removal.
• For batch work, write a Script-Fu or Python script to automate the transparency-removal step.
• Verify the bit depth in File Explorer Properties to confirm the alpha channel is present.

Appendix A: transparency-removal procedure in GIMP — step by step with screenshots in mind

The following procedure documents the GIMP transparency-removal workflow in greater detail than the summary above. The procedure is the foundational pattern that the rest of this article assumes; mastering it makes every subsequent icon faster.

Step 1: open the file

In GIMP, choose File → Open and navigate to the Paint-saved PNG. The image opens as a single layer named "Background" with no alpha channel. The layer is flagged in the Layers panel with a bold name, indicating it is the locked background layer.

Step 2: add an alpha channel

The Background layer cannot hold transparency until it has an alpha channel. Two equivalent methods to add one:

1. Right-click the Background layer in the Layers panel. Choose Add Alpha Channel from the context menu.
2. From the Layer menu. Choose Layer → Transparency → Add Alpha Channel.

After the alpha channel is added, the layer name in the Layers panel changes from bold to non-bold, indicating the layer now supports transparency.

Step 3: select the white background

The selection should include all the white pixels that will become transparent. Two methods:

1. Select by color. Choose Select → By Color (Shift + O). Click any white pixel in the image. All connected and disconnected white pixels are selected. Adjust the Threshold slider to control how strict the color match is (a threshold of 0 selects only pure white; higher thresholds include near-white pixels).
2. Fuzzy Select (Magic Wand). Choose the Fuzzy Select tool (U). Click a white pixel. Only the white pixel and connected white pixels are selected. Use this method if the icon has interior white regions that should remain opaque.

Step 4: clear the selection

With the white pixels selected, press the Delete key. The selected pixels are cleared to transparency. The Layers panel preview updates to show the icon over a checkered transparent background.

Step 5: deselect

Choose Select → None (Ctrl + Shift + A) to clear the selection. The selection marquee disappears.

Step 6: export as PNG

Choose File → Export As. Navigate to the target folder. Enter the filename (the same as the original, or a new variant filename). Confirm the format is PNG. Click Export.

GIMP displays a PNG export options dialog. The defaults are appropriate for game assets:

• Interlacing: off (game engines do not benefit from progressive loading)
• BKGD chunk: off (no background color hint needed)
• Save gamma: off (no gamma hint needed)
• Save layer offset: off (single layer)
• Save resolution: off (no DPI hint needed)
• Save creation time: off (no metadata needed)
• Save color values from transparent pixels: off (cleaner output)
• Compression level: 9 (maximum compression; lossless)

Click Export to write the file. The transparency-aware PNG is saved.

Step 7: verify the export

Open the saved PNG in a viewer that displays a transparency checkerboard. The icon should float over a checkered background. If the icon appears over a white background, the export did not preserve the alpha channel — recheck the Add Alpha Channel step (Step 2).

Appendix B: workflow alternatives for non-Windows modders

The standard 57 Studios pixel art workflow assumes Windows and Microsoft Paint as the authoring tool. Modders on macOS or Linux must use different authoring tools but can follow the same transparency-removal pattern.

macOS workflow

macOS does not include Microsoft Paint. The closest equivalents for pixel art:

1. Preview.app — built-in image viewer with limited editing capabilities. Sufficient for small touch-ups but not a primary pixel art authoring tool.
2. Pixelmator Pro — paid, native macOS, full-featured. Supports transparency natively.
3. GIMP — free, cross-platform. Same workflow as Windows GIMP.
4. Krita — free, cross-platform. Same workflow as Windows Krita.
5. Aseprite — paid, cross-platform, dedicated pixel art tool.

For macOS modders, the recommended path is to skip the Paint-equivalent step entirely and author directly in GIMP, Krita, or Aseprite, all of which support transparency natively. The transparency-removal step in the Windows workflow is unnecessary on macOS because the macOS tools never produce the opaque white background in the first place.

Linux workflow

Linux does not include Microsoft Paint. The available alternatives:

1. GIMP — free, cross-platform. Standard on most Linux distributions.
2. Krita — free, cross-platform. Available through most Linux package managers.
3. Pinta — free, designed as a Linux-native Paint.NET alternative.
4. Aseprite — paid, cross-platform.

For Linux modders, the recommended path is similar to macOS: author directly in a transparency-aware tool and skip the transparency-removal step.

Cross-platform consistency

The PNG file format is identical on every platform. A transparent PNG created in Windows GIMP renders identically to the same file created in macOS Pixelmator Pro or Linux Krita. The choice of authoring tool affects the modder's workflow but not the file's behavior in the game.

Appendix C: transparency in the Unturned asset pipeline

The transparency information set during the Paint → GIMP/Paint.NET workflow propagates through the rest of the Unturned asset pipeline. The following sections document how transparency is preserved (or lost) at each stage.

Stage 1: source PNG file

The source PNG file has the alpha channel set during the transparency-removal step. The file is an RGBA (32-bit) PNG with the icon pixels at alpha 255 and the surrounding pixels at alpha 0.

Stage 2: Unity import

Unity reads the PNG and creates an in-engine texture. The default import settings preserve the alpha channel. Specifically, the Alpha Source setting in the Unity texture importer should be set to Input Texture Alpha (the default for PNG imports).

If the Alpha Source is set to None, Unity discards the alpha channel during import and produces an opaque texture. This is the equivalent of running the PNG through classic Paint — the transparency is lost. Verify the Alpha Source setting in Unity's texture importer before building the asset bundle.

Stage 3: texture compression

Unity applies texture compression during the build. The compression format affects how the alpha channel is stored:

Compression format	Alpha support	Notes
Uncompressed	Yes	Largest file size; lossless
DXT1	Single transparent color (1-bit)	Smaller; suitable for hard-edge icons
DXT5	Full 8-bit alpha	Larger than DXT1; suitable for soft-edge icons
BC7	Full 8-bit alpha	Highest quality; smaller than DXT5
ASTC	Full 8-bit alpha	Mobile-friendly; flexible quality
ETC2	Single transparent color or full alpha	Mobile/Android

For Unturned pixel art with hard edges, DXT1 with 1-bit alpha is typically sufficient and produces small file sizes. For pixel art with soft edges or partial transparency, DXT5 or BC7 is preferred.

Stage 4: asset bundle build

The compressed texture is packaged into an asset bundle. The bundle build does not modify the texture further; the compressed format is preserved exactly.

Stage 5: in-game rendering

Unturned loads the asset bundle and renders the texture in the appropriate UI context. The alpha channel determines which pixels are visible and which are transparent. The inventory grid background shows through the transparent pixels, producing the clean appearance the modder originally intended.

The diagram shows the full pipeline from Paint authoring to in-game rendering. The alpha channel is set at the GIMP step (Stage 2 in this article's terminology) and preserved through every subsequent stage.

Appendix D: transparency troubleshooting matrix

The following troubleshooting matrix covers the most frequently reported transparency-related problems and their resolutions.

Symptom	Likely cause	Resolution
Icon has full white background in-game	PNG saved with no alpha channel	Re-export from GIMP/Paint.NET with alpha
Icon has faint white halo around edges	Anti-aliased edge pixels not removed	Manually clean up edges, or re-author with Pencil only
Icon is fully transparent in-game	Alpha channel inverted	Re-export with correct alpha polarity
Icon has wrong colors against transparent background	Premultiplied alpha confusion	Verify Unity import set to straight alpha
Icon appears with darker edges in-game	Premultiplied alpha applied incorrectly	Switch to straight-alpha export
Icon appears with brighter edges in-game	Straight alpha treated as premultiplied	Verify engine expects straight alpha
Icon shows checkered pattern in-game	Engine misconfigured for transparency	Adjust Unity material settings
Transparent PNG opens opaque in classic Paint	Classic Paint flattens alpha to white	Use a transparency-aware editor
Magic wand selects too many pixels	Tolerance setting too high	Lower the magic wand tolerance
Magic wand selects too few pixels	Tolerance setting too low	Raise the magic wand tolerance
GIMP Add Alpha Channel option is greyed out	Layer already has alpha channel	Skip step; proceed to selection
Saved PNG has 24-bit depth in File Explorer	Alpha channel not saved	Re-export ensuring alpha is enabled

The troubleshooting matrix covers the operational problems most frequently surfaced in the 57 Studios community channels. Problems not addressed here typically trace to engine-side configuration rather than to the PNG file itself.

Appendix E: building a verification habit

The principal cause of white-background problems reaching the destination is the absence of a verification habit. The modder authors the icon, saves it, and assumes it is correct. The destination eventually reveals the problem, and the modder must backtrack to fix it.

A verification habit catches the problem at the authoring stage, before it reaches the destination. The habit is the discipline of opening every saved PNG in a transparency-aware viewer immediately after save, and confirming the transparent regions are visible as a checkerboard.

Verification tools

Several free tools support the verification habit:

1. Windows Photos app. Displays transparency as a checkered pattern. Built into Windows; no installation needed.
2. GIMP. Displays transparency as a checkered pattern. The default viewer mode after opening a PNG.
3. Paint.NET. Displays transparency as a checkered pattern. Familiar interface for ex-Paint users.
4. Web browser with custom HTML. A small HTML file with a dark body background and an img tag pointing to the PNG. Reveals transparency immediately.

Verification checklist

The verification checklist is a short list of items to confirm after every transparency-removal operation:

Step	Verification
1	PNG opens without errors in the verification tool
2	The transparent regions appear as a checkered pattern
3	The icon pixels are at full opacity
4	There is no faint white halo around the icon edges
5	The icon appears identical in size and position to the original
6	The file size is reasonable for the icon complexity
7	The bit depth shows 32 in File Explorer Properties

The checklist takes approximately 30 seconds to complete and catches the great majority of transparency-related problems before they reach the destination.

Appendix F: history of alpha channels in raster image formats

The alpha channel as a per-pixel transparency value did not always exist in raster image formats. Understanding the history provides context for why some formats support transparency and others do not.

Pre-alpha era (1980s)

Early raster image formats (BMP, PCX, TGA) stored only RGB values. Transparency was either not supported at all or was implemented through a designated "transparent color" — a specific RGB value that the rendering software was instructed to treat as transparent. The approach was workable for simple icons but produced visible color fringing around image edges.

Single-color transparency (early 1990s)

The GIF format, introduced in 1987, added single-color transparency through a flag in the file header indicating which palette index should be rendered as transparent. The single-color approach was sufficient for simple icons but could not represent soft edges or partial transparency.

Alpha channel emergence (mid-1990s)

The TGA (Truevision Graphics Adapter) format had supported a 32-bit RGBA mode since the late 1980s, but the format was primarily used in professional imaging contexts rather than for end-user consumption. The PNG format, introduced in 1996, was the first widely adopted end-user format with full per-pixel alpha channel support.

The alpha channel innovation was that transparency could be specified per pixel as a value between 0 (fully transparent) and 255 (fully opaque). The per-pixel approach enabled soft edges, anti-aliased icons, drop shadows, and partial-transparency effects that single-color transparency could not represent.

Modern era (2000s onward)

The alpha channel is now standard in every modern raster image format that supports transparency. WebP, AVIF, HEIC, and modern PNG variants all support per-pixel alpha. The standardization of the alpha channel has eliminated the visible color fringing of the single-color era and enabled the clean icon presentation that game UIs depend on.

For Unturned modding, the alpha channel is the underlying mechanism that makes the inventory grid present icons cleanly over its gray background. Without per-pixel alpha, the icons would have visible white halos around their edges.

Appendix G: alpha channel arithmetic and blending

The alpha channel value determines how a source pixel is blended with the destination pixel. The blending formula is straightforward:

result = source_color * (source_alpha / 255) + destination_color * (1 - source_alpha / 255)

For a source pixel with alpha 255 (fully opaque), the formula reduces to result = source_color, meaning the source pixel completely replaces the destination. For a source pixel with alpha 0 (fully transparent), the formula reduces to result = destination_color, meaning the destination is unchanged. For intermediate alpha values, the result is a weighted blend of the source and destination colors.

Example: alpha 128 (50 percent opacity)

A source pixel with RGB (255, 0, 0) (pure red) and alpha 128 (50 percent opacity), blended against a destination pixel with RGB (0, 0, 255) (pure blue), produces a result of approximately RGB (128, 0, 128) (purple). The result is the midpoint between the source and destination colors.

Example: alpha 64 (25 percent opacity)

A source pixel with RGB (255, 0, 0) (pure red) and alpha 64 (25 percent opacity), blended against a destination pixel with RGB (0, 0, 255) (pure blue), produces a result of approximately RGB (64, 0, 191). The result is closer to the destination (blue) because the source is 75 percent transparent.

Pixel art and alpha values

Pixel art typically uses only the two extreme alpha values: 0 (transparent) and 255 (opaque). Intermediate values produce anti-aliased edges, which are typically not desired in pixel art. The Pencil tool in Microsoft Paint produces only fully-opaque pixels, which is correct for pixel art; the Brush tool produces partially-opaque edge pixels, which is not.

The two-value alpha convention also produces the cleanest visual result in inventory grids and other UI contexts. A pixel art icon with crisp 0-or-255 alpha appears identical in every context regardless of the destination color, whereas an icon with intermediate alpha values may appear with edge fringing in some contexts.

Appendix H: editor-specific transparency walkthroughs in greater depth

The summaries earlier in this article are sufficient for most modders. The walkthroughs below cover edge cases and advanced techniques in each editor.

GIMP: handling disconnected white regions

If the icon has interior white regions that should also be transparent (a window in a building, a hole in a donut shape), the Select → By Color tool selects all such regions at once. The single Delete clears all the white pixels in one operation.

If the icon has interior white regions that should remain opaque (a white logo on a dark background), the Fuzzy Select (Magic Wand) tool selects only the connected white pixels at the click point. Click on the outer white background; the interior white regions remain unselected. The Delete clears only the outer background.

The choice between Select By Color and Fuzzy Select depends on the icon's design. Pure outline icons typically use Select By Color (all white becomes transparent). Iconic logo designs with intentional white regions use Fuzzy Select.

Paint.NET: handling anti-aliased edges

Paint.NET's Magic Wand tool has a Tolerance setting that controls how strict the color match is. For pure white backgrounds, a Tolerance of 0 selects only pixels that are exactly RGB (255, 255, 255). For near-white backgrounds (caused by anti-aliasing or JPEG-like artifacts), a Tolerance of 10 to 30 selects pixels close to white.

A higher Tolerance setting includes more edge pixels in the selection, removing the faint white halo. The trade-off is that the Tolerance may include pixels that should remain opaque (light-colored interior pixels of the icon). Adjust the Tolerance interactively, observing the selection preview, until the right balance is achieved.

Photoshop: the Layer From Background trick

Photoshop opens PNG files as a locked Background layer by default. The Background layer cannot hold transparency. Before any transparency-removal operation, convert the Background layer to a regular Layer:

1. Double-click the Background layer in the Layers panel.
2. The "New Layer" dialog appears with a default name (typically "Layer 0").
3. Click OK to convert the layer.

After the conversion, the layer can hold transparency, and the transparency-removal workflow proceeds normally.

Krita: using Color Range

Krita's Select → Color Range tool is the equivalent of GIMP's Select By Color. The dialog provides a color picker for choosing the target color and a slider for tolerance. After making the selection, press Delete to clear the selection to transparency.

For repeated transparency-removal operations, Krita's Python scripting can automate the workflow. The Krita developer documentation includes example scripts for batch transparency removal.

Aseprite: working with sprite sheets

Aseprite is purpose-built for pixel art and sprite work. For transparency removal from a Paint-exported PNG:

1. Open the PNG in Aseprite.
2. The image is imported as a single sprite frame.
3. Click the Background layer in the Layers panel.
4. Choose Layer → Background → From Background to convert to a regular layer.
5. Use the Magic Wand tool (W key) to select the white background.
6. Press Delete to clear to transparency.
7. Choose File → Save As to write the file with transparency.

For animated sprite sheets with multiple frames, Aseprite's Magic Wand can be applied frame-by-frame or across the entire animation timeline at once.

Appendix I: transparency and Unturned-specific icon conventions

The transparency-removal workflow produces a generic alpha-aware PNG. The Unturned engine and the 57 Studios asset pack conventions impose additional constraints on how the transparency should be applied.

Edge padding

Unturned icons should have a small transparent padding around the icon edges. The padding prevents the icon from touching the inventory cell boundaries, which would visually merge adjacent cells.

The recommended padding for a 64x64 icon is 4 pixels on each side, leaving a 56x56 central drawing area. For a 128x128 icon, the padding is 8 pixels on each side, leaving a 112x112 central drawing area. The padding scales proportionally with the canvas size.

The padding is achieved by simply not painting pixels in the outer ring during authoring. The unpainted pixels remain white during authoring, then become transparent after the transparency-removal step.

Solid icon bodies

Within the icon's silhouette, every pixel should be at full opacity (alpha 255). Interior transparent pixels are a frequent cause of icon appearance bugs in-game. Verify after transparency removal that the icon body is fully opaque.

The standard check is to view the icon over a dark background (in the Windows Photos app, against a black HTML page, or in a transparency-aware editor with a dark canvas background). The icon should appear with no see-through regions in its body; only the surrounding area should be transparent.

Anti-aliased outlines

The hard-edge convention of pixel art means the icon's outline should be a single line of opaque pixels, not an anti-aliased gradient. If anti-aliasing was introduced (by use of the Brush tool, by import from a non-pixel source, or by a non-integer resize), clean up the outline manually using the Pencil tool before the transparency-removal step.

The result of a hard-edged outline is an icon that scales cleanly through the Unity pipeline and renders crisply in-game regardless of the rendering resolution. The result of an anti-aliased outline is an icon with edge fringing that varies with rendering conditions.

Cross-references

• How to Open Paint — launching the Paint application.
• How to Use the Pencil Tool — placing pixels with hard edges (avoiding anti-aliasing).
• How to Use the Eyedropper Tool — sampling color for consistent palettes.
• How to Zoom In for Pixel-Level Editing — examining individual pixels at high magnification.
• How to Set Canvas Size for Icons — sizing the canvas before authoring.
• How to Save a PNG File in Paint — saving the file from Paint.

Appendix J: workflow scenarios for transparency-removal

The following workflow scenarios illustrate the transparency-removal step in realistic asset-pack contexts.

Scenario 1: first icon, first transparency-removal

A new modder has just completed their first pixel art icon in Paint and is encountering the white-background problem for the first time. The recommended workflow:

1. Install GIMP (free, available from gimp.org or through the Windows Store).
2. Open the Paint-saved PNG in GIMP.
3. Follow the step-by-step procedure in Appendix A of this article.
4. Verify the transparency by opening the exported file in the Windows Photos app.
5. Move the verified file into the mod's asset folder.

Total time: approximately 5 minutes for the first icon, dropping to 1 minute per icon once the workflow becomes routine.

Scenario 2: batch transparency removal

A modder has authored ten icons in a single Paint session and needs to add transparency to all of them. Manually opening each file in GIMP is repetitive. The recommended workflow:

1. Place all ten Paint-saved PNGs in a single folder.
2. Open GIMP's Script-Fu console (Filters → Script-Fu → Console).
3. Use a Script-Fu script to iterate over the folder, removing white backgrounds from each file.
4. Verify the outputs by spot-checking a sample of the files in the Windows Photos app.

The Script-Fu approach scales to hundreds or thousands of icons. The script itself can be saved and reused across asset packs.

Scenario 3: re-transparency after edits

A modder has edited an existing transparent icon in classic Paint, which flattened the transparency to white. The icon now has the white-background problem again. The recommended workflow:

1. Open the now-flattened PNG in GIMP.
2. Apply the transparency-removal procedure.
3. Verify the transparency.
4. In the future, edit transparent icons in GIMP or Paint.NET, not in classic Paint, to preserve transparency across edits.

The discipline reinforces the principle that transparent files should stay out of classic Paint after the initial transparency removal.

Scenario 4: rescuing an old asset pack

A modder is updating an old asset pack that was authored entirely in classic Paint and never received the transparency-removal step. Every icon has the white-background problem. The recommended workflow:

1. Inventory all the PNG files in the asset pack.
2. Use the batch transparency-removal approach (Scenario 2) to process all files at once.
3. Verify a sample of the outputs.
4. Re-build the asset bundle with the updated files.

The rescue workflow is the standard fix for legacy packs that were created before the transparency-removal discipline was established.

Scenario 5: handling complex icons with intentional white

A modder is authoring an icon that intentionally contains pure white pixels in its body (a white logo, a white symbol on a colored background). A naive transparency-removal would also clear the intentional white pixels.

The recommended workflow:

1. Open the PNG in GIMP.
2. Use the Fuzzy Select (Magic Wand) tool, not Select By Color.
3. Click on the outer white background. Only the connected white pixels are selected.
4. The interior white pixels (the intentional white) are not selected and remain opaque.
5. Press Delete to clear only the outer background.
6. Verify that the intentional white pixels are still opaque.

The Fuzzy Select approach is the correct tool for icons with intentional white regions. The Select By Color approach is correct for icons with no intentional white.

Appendix K: extended FAQ on transparency edge cases

Why does the icon look correct in some apps and wrong in others?

Different apps render PNG files differently. Some apps render against a white background by default (Windows File Explorer thumbnails, the Windows Photos app, default web browsers). Other apps render against a dark or checkered background (Discord avatars, the Unturned inventory grid, image editors with transparency-aware previews). An icon with a white background looks correct against a white app background and wrong against any other background.

Can I save transparency-aware PNG from classic Paint by holding a special key?

No. There is no key combination that enables transparency-aware saving in classic Paint. The application does not have the capability built in. Transparency-aware saving requires a different editor.

What happens if I open a transparency-aware PNG in classic Paint?

Classic Paint reads the PNG but loses the alpha channel. The transparent pixels are rendered as white in the Paint canvas. Any save operation from classic Paint produces an opaque PNG, losing the transparency.

Can I tell from the filename whether a PNG has transparency?

No. The filename does not indicate the presence or absence of an alpha channel. Both opaque and transparent PNGs use the .png extension. Verify transparency by opening the file in a transparency-aware viewer or by checking the bit depth in File Explorer Properties (24-bit = opaque, 32-bit = transparent).

Does the Unturned engine require transparency for icons?

The Unturned engine accepts both opaque and transparent icons, but the visual result is different. An opaque icon appears as a white rectangle around the icon artwork in the inventory grid. A transparent icon appears with the icon artwork floating cleanly on the inventory grid background. The transparent appearance is the expected and conventional choice for Unturned icons.

Can I add transparency to an icon that has already been compressed for Unity?

The compressed Unity texture cannot be edited directly. To change the transparency, return to the source PNG file, apply the transparency-removal step, and re-run the Unity import. The compressed Unity texture is regenerated from the source PNG.

How does transparency interact with anti-aliasing?

Anti-aliasing produces edge pixels that are partially the icon color and partially the background color. When the background color is removed (set to transparent), the edge pixels retain their partial coloring. The result is an icon with a faint colored halo at its edges. The halo is the visible artifact of the anti-aliasing.

For pixel art, anti-aliasing is typically not desired. Use the Pencil tool exclusively in Paint to avoid producing anti-aliased edges. Use Aseprite or a similar dedicated pixel-art editor for projects where anti-aliasing control is critical.

Can I use transparency to create a fade effect?

Yes, using intermediate alpha values. A linear gradient from alpha 0 (transparent) to alpha 255 (opaque) produces a fade effect. The fade is rendered correctly by any transparency-aware viewer or engine.

For Unturned modding, fade effects are uncommon but supported. Most icons use only the two extreme alpha values (0 and 255) for crisp, hard-edged appearances.

Does the resolution affect transparency?

No. Transparency is independent of resolution. A 64x64 transparent PNG renders with the same per-pixel alpha as a 512x512 transparent PNG. The alpha channel scales with the resolution; each pixel has its own alpha value regardless of the total pixel count.

Can I see transparency in the Microsoft Paint canvas?

In classic Paint, no. The canvas always appears with a white background, regardless of whether the original file had transparency. In modern Windows 11 Paint with transparency support enabled, transparent regions appear as a checkered pattern on the canvas.

Appendix L: relationship between transparency and other pixel art concepts

The transparency concept connects to several other pixel art topics covered elsewhere in the wiki. The cross-connections are worth understanding.

Transparency and canvas size

Canvas size is set during the initial Paint session, before any pixels are placed. The canvas size determines the total pixel count and the icon's working area. Transparency is set later, after the icon has been authored, by removing the white background. The two concepts are independent but related: a canvas of the wrong size cannot be corrected by transparency-removal alone.

Transparency and the Pencil tool

The Pencil tool produces hard-edged pixels with no anti-aliasing. The hard edges make transparency-removal straightforward because the Magic Wand can cleanly distinguish icon pixels from background pixels. The Brush tool produces soft anti-aliased edges, which complicate transparency-removal.

Transparency and the Eyedropper tool

The Eyedropper tool samples the color of any pixel in the canvas. For pixel art with consistent palettes, the Eyedropper is used to sample existing icon colors when adding new icons. The Eyedropper does not interact with the alpha channel; sampled colors are returned as RGB values without an alpha component.

Transparency and zoom

High zoom levels are essential for examining individual edge pixels and verifying that the transparency-removal step produced clean output. At low zoom levels, edge artifacts (faint halos, stray pixels) are not visible. At high zoom levels, every pixel is inspectable.

Transparency and the save step

The save step writes the canvas to a PNG file. The save step is independent of transparency; the same Save As workflow applies whether the file has an alpha channel or not. The difference is the source: classic Paint always writes an opaque file, regardless of the canvas state; transparency-aware editors write whatever the canvas contains.

Document history

Version	Date	Author	Notes
1.0	2024-03-04	57 Studios	Initial publication. Cause analysis, GIMP/Paint.NET/Photoshop workarounds.
1.1	2024-05-22	57 Studios	Added decision flowchart, pipeline diagram with highlighted transparency step.
1.2	2024-09-11	57 Studios	Expanded editor comparison, added Krita and Aseprite workflows.
1.3	2025-02-14	57 Studios	Added verification procedures, restructured FAQ, expanded best practices.
2.0	2026-04-30	57 Studios	Major expansion. Added four-channel pixel model section, alpha visualization, cross-platform workflows, troubleshooting matrix, verification habit guidance.

Next steps

This article concludes the Pixel Art section. You can now produce icons in Paint, sample colors with the Eyedropper, zoom precisely, size canvases correctly, save as PNG, and resolve the transparency issue with a downstream editor. The next stage of the modding pipeline is bringing those icons into Unity. Continue to How to Install Unity Hub.