Here are some gels for experimenting.

The Smith-Victor gels are 12x12.

The Rosco gels are 10x12.

The ND gels are 8x10.

Some gels have creases or wrinkles.  A couple have toner transfer from being stored on top of a laser printed page.  Some may have other defects.  Most are OK, especially if you'll be using smaller pieces.

Most of the Roscoe gels have had 1/4 removed already.  See photos.  

Thanks for looking.