On 24-Dec-2005, (Steven Swift) wrote:

Anyone have one good for a 3" round CRT or know of a good substitute
material (perhaps from a hobby store)?

Look up your local theatrical supply house in the phone book. See if they
are a Rosco dealer.
http://www.rosco.com/us/retail/index.asp

Rosco makes sheets of gels in many different colors. There must be one close
enough for what you want to do. Plus, they are very robust in that they have
to stand up to extreme heat.