A couple of suggestions to make the staining a little less is to either stamp first in a light color ink and then stamp that off, then use the color you planned to stamp with. You'll only need to do this the first time you use them. If you use something like a colonial white or a yellow, then your stamps won't stain a darker color. Also, some report that if they stamp in the Versamark after using a color and let it sit for a few minutes, some of the ink color will come off.
I've not done either of these as I don't mind the staining, so, I'm just reporting what I've read
Suz
http://www.suzastampin.com