Removing Blemishes in GIMP

Removing blemishes in GIMP is a matter of covering a spot with nearby skin texture that blends in naturally. The Heal tool does this automatically - it samples from a source area and blends the texture while matching the tone and color of the target area. It is far more natural-looking than the Clone tool for skin work.

Using the Heal Tool

1. Press H to activate the Heal tool (in GIMP 2.10+).
2. Set the brush to a size slightly larger than the blemish you want to cover. Use a soft brush (50-70% hardness).
3. Sample the source area: Hold Ctrl and click on clean skin nearby - same tone, same lighting as the blemish. This sets the source point.
4. Release Ctrl. Click (or brush) over the blemish. The Heal tool copies texture from the source and blends it to match the local tone of the target.

Sample from an area close to the blemish - within a centimeter on the printed photo equivalent. The closer the source, the better the texture and lighting match will be. Re-sample (Ctrl+click) for each new blemish location rather than using one source point for the whole face.

Using the Clone Tool as a Backup

If the Heal tool is leaving artifacts (sometimes happens near sharp edges or strong color boundaries), switch to the Clone tool:

1. Press C to activate the Clone tool.
2. Ctrl+click to set the source point on clean skin.
3. Paint over the blemish.

The Clone tool simply copies from the source with no blending. For blemishes in the middle of uniform skin texture, it works fine. For blemishes near edges or color transitions, the pixel-exact copy can look mismatched - that is when Heal is better.

Retouching on a Separate Layer

Always retouch on a new layer, not directly on the original photo:

1. Duplicate the photo layer (Shift+Ctrl+D).
2. Work on the duplicate. Keep the original hidden below as a backup.

Or, for the Heal and Clone tools specifically, enable Sample Merged in Tool Options. Then create a new empty transparent layer above the photo and paint on that. The tools will sample from the original photo layer but paint only on the empty layer - the original stays intact.

Working on a separate retouch layer is especially important for skin retouching where you may want to compare before and after by toggling the retouch layer visibility.

Tips for Natural-Looking Results

• Do not over-retouch. Removing every pore and skin texture looks unnatural. Target only visible blemishes and leave underlying skin texture intact.
• Use small brushes. A brush only slightly larger than the blemish gives more control than a large brush that blurs a wide area.
• Zoom in to work, zoom out to check. Retouch at 100% zoom or higher, then zoom to 50% or actual viewing size to check if it looks natural.
• Watch for repetitive patterns. If the source texture repeats visibly, re-sample from a slightly different spot.
• Combine with the Smudge tool. After healing, a light Smudge pass at 20-30% rate can blend any remaining edge artifacts.