Why does a transparent product cutout have a white halo?

Locate the halo in the source

Place the same cutout over a pale, middle-gray and dark background in an external editor. Keep its size and position fixed. If the outline changes with the backing while the product interior stays stable, inspect the mask and edge colors. A uniformly bright outline and a directional metallic highlight are different clues.

For an illustrative black kettle, compare the rim with the actual photograph. A reflection facing the light may be genuine. A pale fringe surrounding the handle on every side may come from the original backdrop or export treatment. Use the physical reference to decide which is which.

Separate three edge problems

These are diagnostic candidates, not automatic repair instructions. Work on a copy and keep the untouched reference available.

Choose a repair appropriate to the product

An external masking or edge-decontamination workflow may help a contaminated cutout. A new photographed reference can be better when a fine transparent edge is missing. Itemlume does not currently provide a dedicated precision cutout or edge-repair tool. Generation may interpret the boundary differently and still needs comparison.

Approve against the intended placement

After repair, inspect the product at the actual display size on the proposed background. Include thin handles, glass lips and cables, not only the largest edge. Retain a brief note naming the backing used for approval. The white-on-white guide handles scene readability; the topology guide handles missing openings. Neither alone establishes a clean alpha edge.

A backing-color diagnosis example

Suppose a dark kettle cutout appears clean on white but shows a pale outline around its handle on gray. Its real source shows a bright highlight only on the upper rim. Mark those regions separately: preserve the directional highlight and ask the external editor to inspect the handle mask. After a repair, compare the same scale on all three backgrounds. If the handle becomes thinner, reject that repair even if the halo disappears. The acceptance question is whether the product boundary remains accurate on the intended backing, not whether every bright pixel has vanished.