Note: To protect the privacy of our members, e-mail addresses have been removed from the archived messages. As a result, some links may be broken.
I got mine when I bought an existing custom framing business.
I'm sure I've seen them in the framing sections of some art supply
catalogs - like maybe Dan Smith or Dick Blick or Sax. I don't know who
actually makes them. They are small, about 1" square, but well worth the $6
or whatever they cost. (and cheaper than a frame shop!)