Make & keep
Hide a prop edge in GIMP with a reversible layer mask
Refine a cutout by painting on its mask instead of erasing the photo pixels.
A party prop can overlap a portrait edge in a way that calls for a careful cutout. A GIMP layer mask controls which parts of a layer show; painting on that mask lets you revisit the edge later. Start with a duplicate layer so the original remains available.
Add a mask
Select the duplicate layer and choose Layer → Mask → Add Layer Masks. Choose White (full opacity) to begin with the layer visible. The mask thumbnail appears beside the layer thumbnail; click the mask thumbnail before painting.
Evidence: Official product documentation
Refine the boundary
Use a soft brush at a modest size and paint black on the mask to hide stray background or prop pixels. Paint white to restore areas that disappeared. Zoom in near hair, clothing, and frame borders, but periodically zoom out to judge the whole portrait.
Evidence: Official product documentation
Check the result
Toggle the layer’s visibility to compare the edit with the untouched image. Inspect against both a light and dark temporary backing so pale halos are visible. Keep the mask in the saved layered file; do not apply it until a separate flattened copy is approved.
Evidence: Official product documentation
Sources & further reading
Sources for the specific facts and product descriptions above. Our worked examples, interpretations and practical suggestions are original editorial guidance.
- GIMP 3 User Manual — Add Layer MasksOfficial product documentation