I don't know that it is required that you use a stamp, but they should be hand made. The rules for each swap should be posted in the first post of the thread. If you are concerned about it, you can always check with the hostess.
Lorien <--My Blog
Giggle Mingler (Hee hee)
"A raω onion ωould pгοbably be rubbеd on unbroken сhildbrainѕ with гeрutablе gaіns." - Comment from a Blog Spammer as Read by me