I was recently making my Japanese Style Puff Pancakes and could not find my metal ring mold ANYWHERE! So I used a shaped one. Yesterday, I realized I could just make one out of wax paper. These DIY ring molds work great when you want your pancakes or eggs to stay in a perfect circle shape, like when you're making Egg McMuffins. Just cut a strip of wax paper, staple to secure, and pour in liquids.
Link: Japanese Style Puff Pancakes
I don't recommend paper rings.
The sides aren't stable enough for a nice, clean flip.
Upon flipping sides will tend to cave in almost every time.
Don't frustrate yourself, use something metal: rings, cookie cutter, tuna cans all would work.