I have two grafmatics for my 2x3 and both will fit both Graphic and Graflex backs - they have both the ridges and the slots.

Is this the way all of the Grafmatics in this size were made? I have cameras with each back and I want to get more Grafmatics that will work in both cameras. I'm wondering if all will do that or if I just got lucky.

Do you mean Graflex back or Graflok back? The GraFLEX back uses holders that are larger than the ones that fit the Graphic and Graflok backs. They do not interchange. I have never seen Grafmatics for the Graflex back. They used bag mags. As to the others, they are the same for spring (Graphic) and Graflok backs.

Graphic back (on a miniature speed) and Graflex back (on a "B" RB). On the 2x3 they are the same width. The two Grafmatics I already have have both the slots on the sides and the ridges. They fit both cameras.

It sounds to me like you have something quite unusual. I don;t know if you would be able to find any to match them.

I just snagged what appears to be a late-model 2X3 Grafmatic which has a slot for SLR use as well as the ridge for Graphic-back cameras. The auction pics bear this out:

http://www.ebay.com/itm/301296652002?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Here's a pic of the holder uploaded to flickr: https://www.flickr.com/photos/47932393@N04/15150319832/in/photostream/

I don't have a Graflex 2X3 SLR to test it on but will try it out on the Century when it arrives and update this report.

I have two "23" Grafmatic 2 1/4 x 3 1/4 film holders. except for the lettering on them I can not find any difference from the posted photos so I would assume that yours are the usual model just several years newer than mine.