On a white background, using the marquee tool, I draw an anti-aliased circle, fill it with a blue color (anti-aliased on) and invert the selection.

If I take a white paintbrush and go around the edges of the circle while holding the mouse button, nothing really happens.
If I go around the circle with the same paintbrush and press/let loose of the mouse button a couple of times, it will remove the anti-alias. I don't understand that. Why does it remove the anti-alias after a few strokes? It's easy to deal with this problem, if I just have to use a couple of strokes, but otherwise it can be frustrating.

I use this technique to round one corner of a square. Inside the square I position a circle marquee, invert it and go round it with a white brush (in case I have a white background)

Look at the attached picture. The lower half is done by holding the mouse button, the upper half is done by clicking a couple of times.

I hope somebody can shine a light on this problem.

http://www3.sympatico.ca/maiziev/test.jpg

[This message was edited by Gaussian on March 11, 2002 at 09:42.]