http://forums.catholic.com/forumdisplay.php?f=1
You could find a Catholic site like that one - they have a questions forum - and ask them, if you'd like to know for certain if there are rules pertaining.
We were taught as (Catholic) tots though, that it's all about intention. If you mean well, it's all good. I'd glue it and bless him. HE knows you mean well, and that's what counts.