Dark Edges After Importing Spine Art? Check the Alpha Handoff First

The reused AI-generated cover illustrates two backgrounds. Its checkerboard is painted content, not proof of transparency, and the image is not a PMA-versus-straight-alpha rendering test.

A character develops dark edges after entering the game project. Before asking AI to repaint its parts, preserve the original delivery and record where the difference first appears: workbench preview, source-image viewing, or target-project rendering. This is a handoff checklist, not one universal set of engine switches.

A PNG extension does not identify the alpha workflow

PMA means premultiplied alpha; straight alpha uses unassociated color values. The official spine-unity Assets documentation describes separate texture workflows with corresponding import and material settings. The chain must agree; the filename extension alone does not establish that agreement.

Those settings have a specific runtime context. Do not copy Unity material parameters into another engine or rely on an older tutorial's defaults. If the actual export information does not establish the alpha convention, record it as unknown. Do not invent a convention for a particular Tooliva export.

Keep a baseline that cannot be overwritten

Retain the original package and textures, then work in a test copy. Record the export date, filenames, and paths actually loaded by the project. Ask the integrator to confirm that old atlas or texture files are not being mixed in. Avoid cropping, resampling, converting, or recompressing before this baseline comparison.

If the delivery needs checking in Spine Workbench, use the public guide to identify the resource and export batch. This article does not claim that the workbench provides an undocumented PMA conversion control.

Include five fields in the handoff

1. Source: the original package and actual texture, including any conversion history.
2. Alpha convention: evidence from the export, or explicitly unknown.
3. Environment: actual engine and Spine runtime versions, plus project color space.
4. Rendering path: the material or shader and texture import settings in use.
5. Symptom: background, display size, animation, and first stage showing the dark edge.

These are proposed human records, not an automated Tooliva diagnosis. The recipient should use documentation for the project's actual runtime version rather than treating a cropped screenshot as the complete report.

Keep the source fixed while checking a matching configuration

In the test copy, hold the original texture, background, display size, and animation constant and record the starting result. When a mismatch is established, the integrator can apply the complete matching import-and-material configuration described for that runtime. Record exactly what changed; a single toggled parameter does not validate the entire chain.

Do not repeatedly premultiply the original image, or try unpremultiplication followed by compression without knowing the source convention. If the workflow matches and artifacts remain, investigate source-edge colors, filtering, scaling, and neighboring atlas content separately. Dark edges do not prove one particular cause.

Accept observed behavior, not a smaller file

Check the real project background and display size in still views and full motion, then add light and dark background observations. One preview does not cover every skin, material, or device. Keep the result for each required case and list unresolved differences.

The color and alpha-edge compression guide covers source-quality concerns. This article adds the alpha-workflow handoff; it does not replace the integration documentation.