I need to make 12" and 8" squares for a wedding cake but don't have good pans in those sizes. I have the Wilton 12" but the corners and edges aren't crisp enough for me. I want to purchase a pan that will be multi-functional; I'd like to use it for all size square cakes. I've seen on cake decorating shows that sheet pans are used and then a square template to cut the size wanted. What sheet pan is this that they use? I've tried searching for sheet pans 1" deep but don't find any. Are they using jelly roll pans?

Thanks in advance for the help!

They're using full size sheet pans that fit into professional sized ovens. They measure 18 x 24.

They're called Bun pans - 18" x 26":
http://www.katom.com/009-18A262X.html
Also available at Sam's Club (sometimes called Jelly Roll pans too.)

When baking cake, bakeable cardboard trays are used (25 1/4 x 17 5/
http://www.newmethodpackaging.com/catalog.asp?prodid=606125
(the "cool" emoticon is suppose to be an eight)

Thank you so much for the responses!