A character looks clean on the artist’s canvas but develops a dark fringe when placed over a pale background. Before repainting every edge, check how the exported transparency is being interpreted.
An alpha channel describes opacity. Straight and premultiplied representations handle the relationship between colour and opacity differently, particularly in partially transparent edge pixels. A receiving application needs to interpret that relationship correctly.
Adobe’s footage-interpretation documentation illustrates a black halo caused by reading premultiplied material as straight. This is a possible cause of a fringe, not a diagnosis for every damaged outline.
Test the edge on more than one background
Use a short section of the actual exported sequence. Place it over a light background and a dark one, then inspect a few frames with fine hair, motion blur, or another soft edge.
Check the export settings and the import interpretation together. Avoid changing both randomly: otherwise an improvement may hide which setting was wrong, and the next person receiving the file will repeat the problem.
Keep a reference still of the intended appearance. If the fringe remains after the interpretation is correct, investigate other causes such as a matte left in the source artwork, filtering, or an unsuitable export format.
Include the transparency convention in the handoff
For a small animation team, the delivery note can identify the file format, alpha representation, and any matte colour used. That is more useful than a message saying only “transparent background included.”
Reopen the final delivery in the destination application, not just in the software that created it. A checkerboard preview confirms that some transparency exists; it does not demonstrate that semitransparent edges will composite correctly.
The goal is to preserve the artist’s intended contour through the pipeline. A settings mismatch should be resolved at the handoff rather than disguised by erasing or thickening the character’s linework.