How can I attach printed rice paper decorations to cakes / cookies?
When I've seen them used, they first frosted the cake, smoothed it out, then placeed the rice paper on top.

My understanding is that the moisture in the frosting can end up melting the rice paper, so that it basically disappears into the frosting, with the ink effectively transfering into the frosting.

As I've never done it myself, I have no idea if there are any special tricks to it, or if you need to use a particular frosting / icing recipe so that the paper will melt away.

update: after a little research, I have reason to believe that normal rice paper won't disolve into the cake but there are special 'frosting sheets' that will.  another recomendation was to leave enough white space around the image so that you can cover the edge of the sheet with a border if it starts to curl up.