How do I determine the thickness of my letters?

The easiest way to determine if you have a flex or rigid letter is to compare it to the thickness of a credit card. If it's the same or slightly less, it's a Flex letter. Anything thicker is a Rigid letter, and Rigid letters don't fit into Flex letter track. It's actually the type of track on your sign, the strips that hold the letters, that determines what type of letter you have or will need. Flex letters don't work with rigid letter track, and rigid letters don't work with flex letter track. Rigid letters typically start out at the two credit card thickness (sometimes called an “econo” letter) and go up from there.