White, black and transparency do not have a universal meaning across image-editing masks. Read the receiving tool's mask contract before uploading one. A layer mask that makes a subject visible in an editor is not automatically a permission map telling an AI system which pixels it may regenerate. A convincing black-and-white preview can still have the opposite meaning from the one you intended.
Identify which kind of mask you have
GIMP documents white as opaque and black as transparent in a layer mask. That is a visibility rule for an attached layer. A generative editing interface may instead ask for a selection, a separate mask image, or an alpha-bearing asset, according to its own documented workflow. Google's inpainting documentation, for example, describes a separate black-and-white mask input; do not infer its full contract from the appearance of a GIMP layer mask.
Check the current tool and model's instructions, including whether an uploaded mask is accepted at all. A document for an older or different endpoint is not permission to assume identical behavior in a newer interface. This guide does not claim Imagild supports importing arbitrary masks or that any particular color always means editable.
Test a harmless, unmistakable rectangle
Prepare a disposable test image with two clearly different areas and no personal or valuable content. Make a simple rectangle where a change would be easy to recognize. Record whether the mask file uses grayscale values, transparency, or a tool-specific selection, and preserve an untouched copy.
| Field | Record before the test |
|---|---|
| Receiving workflow | Exact tool, mode and documented mask type |
| Intended editable area | One named rectangle |
| Protected area | Everything outside that rectangle |
| Alignment | Image dimensions, mask dimensions and orientation |
| Observed result | Which region actually changed |
This is a proposed user test, not an executed benchmark. If the tool offers a reliable editable-area preview, inspect it before any generation. If a paid probe is necessary, make it an explicit budget decision rather than automatically sending a valuable photograph through trial and error.
Check more than black versus white
The mask and source must align. A resize, crop, rotation, or orientation mismatch can place a correct-shaped mask over the wrong subject. Also read how the interface treats soft edges and intermediate values. Do not assume that gray means a precise percentage of creative change, or that transparent pixels are interpreted the same way as black ones.
When moving between tools, export the required mask format rather than only a screenshot of its preview. Keep a visible labeled reference for humans separate from the actual machine input. An arrow or caption added to explain the mask should not accidentally become part of the source image.
Accept the protected area as well
After the test, inspect both the allowed rectangle and the protected surroundings. Even a correctly interpreted mask does not establish perfect preservation unless the resulting file passes your review. Save the convention, dimensions and observed behavior in the project record. Repeat that check when the receiving workflow changes, instead of relying on a color rule learned from a different editor.