Quarter plate film sheath

Does anybody know a source of 3.25x4.25 film sheaths? I've a dozen glass plate holders and am failing to work out an adequate solution.

Somewhere I read that you can cut down glass and use low-tack adhesive, but I'd like something a little less sticky.

Alternatively, has anybody here made some?

Yes, I made some film sheaths, in the 3A size. You need some thin aluminum. In the US hardware stores carry K&S brand sheet metal, don't know what the sources are in the UK.

You obviously want one as a reference of how to bend them.

I notch the corners to size, but leave the sheet oversize. Then bend up one side, past 90 degrees of bend, so that you have a solid bend. Then trim it to the proper size, then finish the bend.

It will probably take a failure or two to figure out the right place to start the bend, as the "slot" will get smaller as you bend the metal over.

Test the size with a genuine sheet of quarter plate sheet film.

You should paint it flat black when you're done.

Haunt the photo swap meets in your area. Although sadly their numbers are dwindling, they can still be good sources for such items as old wooden plate holders, most of which have sheaths in them.

I brought 6 quarter plate (3 1/4 x 4 1/4) holders on Ebay (new in the boxes, believe it or not), not realizing they were for glass plates, not film. I watched Ebay and finally found enough of the appropriate film sheaths. Just program the Ebay search engine and sit back and wait. Film sheaths are fairly common items on Ebay. The only size I've never been able to find is 3 1/4 x 5 1/2. I finally gave up and made myselt a set out of brass sheet metal.