Are you referring to the ones used when making wired flowers? GSA sells them but...there was a security issue in recent months and many CC members (including me) had their credit cards compromised.
I have a Wilton flower/leaf veiner I bought at Hobby Lobby. It has a groove on the back of it to use just like the cel board. Only problem would be if you had to make multiple pieces, it could get tedious. HTH