I always use the NFSC and Antonia's royal recipes for my cookies and I find that sometimes, if I am icing the cookies in just white - when they dry they look as if the royal icing is "greasy"? That's the best word I can think of to describe it - basically the white becomes patchy and parts of the frosting look kind of discoloured.
Anyone experience this?? Could it be because I haven't let the cookie dry enough? I'm stumped.
I have had this happen to me. I have posted about it but nobody seemed to know why. I think it's the butter in the cookie seeping through the royal icing to give it the oily spots. It makes me crazy when this happens because you have no idea the cookies are going to do it until they dry. If I had a picture i would post it. Do you have a picture for us so others can see what we are talking about? Maybe we creamed the butter too much or maybe not enough. Don't know. Anyone out there have a theory?