Just wondering if I could use canned frosting to stencil cookies? Need to make 8 cookies, so don't want to make up a batch of icing for such a small number. Know not to use the whipped icing, but thought I may be able to use the regular frosting such as the Betty Crocker in the cans. I will be stenciling on top of iced cookies. Thanks.

You probably could, but I would thicken it up with a little powdered sugar. Canned frosting is much thinner and may pull some of the print away when you lift off the stencil. Add some sugar and do a test on a piece of parchment paper or something to see which way will work better. 

Canned icing gets *very* soft/melty when it is stirred so as ypierce82 said, add a bit of powdered sugar to stiffen it some.  Don't add too much......be careful and add just a couple of tablespoons to start with until you feel it is stiff enough for your needs.