garageCube

(could someone make this into a sticky?)


I'm reposting a fix for this recurring problem here.

to prevent a white fuzz on the edge of alpha channels do the following.
paste the mask into an alpha channel.
do not have the same info in the RGB channels that is in the mask- this is what causes the fuzz..

eg to have a black shape, make sure the whole of the image is black, with the mask in the alpha channel.

this artifact is caused by overlaying pixels in the mask and the RGB channels having the same values...

This is how I made it according your description:
In Photoshop
make black image RGB
make your shape selection(square, circle…)
select> inverse
select> save selection (channel> new and give it a name)
save as> photoshop (psd) with all layers