Tool help
Smart Knockout
Removes the background color but keeps the same color where it appears inside your artwork.
Best for
Logos, clipart, and AI-generated PNGs where the background color also appears inside details like white lettering.
Simple steps
- Pick the background color with the eyedropper or click Auto-sample corners.
- Raise Tolerance until outside background disappears.
- Keep Edge-connected only on to protect interior matching colors.
- If edges are harsh, raise Feather to 1-2 px.
- If tiny dots remain, raise Despeckle by 1.
What each setting means
Background color
The color to remove from the outside background.
Auto-sample corners
Samples the image corners to guess the background color quickly.
Tolerance
How close a pixel must be to the target color. Low is strict, high is broader.
Edge-connected only
On removes only matching pixels in shapes that touch the image edge or sit directly next to a transparent area. Interior matching colors that are surrounded by other opaque colors are preserved. Off removes every matching pixel.
Feather (px)
Softens the knockout edge by blurring the mask boundary.
Despeckle
Removes tiny matching speckles before knockout to avoid little leftover dots.
Grow / shrink mask (px)
Positive expands the cut (for halos). Negative tightens it (to keep thin edge detail).
Remove large interior regions
When on, big interior matching regions are removed too. Useful when only small interior whites (eyes, teeth, dots) should remain.
Max interior area to keep (px)
Only used when remove-large-interior is on. Interior matching islands larger than this pixel area are removed.
Helpful tips
- Use Auto-sample corners first, then fine-tune with Tolerance.
- If interior detail disappears, lower Tolerance or raise Despeckle by 1.
- If too much interior white remains, turn on 'Remove large interior regions' and lower the area threshold.
- Use Grow +1 or +2 to clear light fringe halos on the edge.
- For a hard print-ready edge, run Solid Alpha after Smart Knockout.
Deep-dive notes
- Smart Knockout is different from Remove / Replace Color. Smart Knockout protects interior matching colors when they are not connected to the edge.
- Connectivity is 8-directional, so diagonal pixel links still count as connected.
- On artwork that is already on a transparent background, only matching colors directly next to that transparent area are removed. Letters and outlines several pixels inside the design are preserved.
- Already-transparent pixels stay transparent and do not become opaque.