Jody -- email sent.
I made a 12" x 10" holder for a camera that I built. As I was in control of both parts I did not have to make it to fit any established standard which made it more straightforward. I used strip wood from my local model shop, mostly spruce. It is made to reasonably tight tolerances so there was no problem there. I used good quality ply for the core and the slides were black Formica. It was completely successful. good luck with yours.
This link might help too
Been a stringed instrument maker in Woodstock NY since 1977 and elsewhere for another 10 years. Everything you bring to the project is important. Tools, experience desire to be accurate... but the wood is "in charge". When wood is dried by air, slowly or by heat or dehumidification kilns quickly it builds tension inside. When you mill it to size you release this stored tension and the wood moves. Maple and mahogany are known for this.... so rough cut all parts let the pieces stablize for a month an inch of thickness, than make your finish cuts for assembly. Swiss pear ($$) is the most stable wood(used for jack slides in harpsichords) you can use... domestic pear, which can be hard to find commercially (I cut my own tree in 1983) is good walnut is also very good but has a great deal of variation in density so it is important to pick pieces of similar density. Sapele , a mahogany look alike is used in the piano industry for piano hammers because of its stability but it is HEAVY. Paduk is very stable and less heavy than sapele. Some commercial builders of film holders offer this very attractive orange wood. Be careful to use quarter sawn or flat sawn woods for stability. Age of the wood is also very important, but adds to the cost because of the cost of proper storage. My instruments are made of materials no less than 10 years old and often 3 or 4 times that. By the way, I do have extra supplies of these fine woods and would consider selling some for the "spirit" of large format. William Kramer-Harrison, Luthier.
I just bumped into this post, it reminded me of my 8x20 filmholder project here:
Making ULF holders is a bit more involved than making a doghouse...
About the only soft wood I would consider might be sugar pine often called pattern maker's pine. It is stable and the grain is such that it can be carved pretty freely in all directions - and as the nickname would suggest it was used for foundry pattern making because it could hold detail well. From a woodworking perspective it's only real fault is that it won't sand smoothly enough to take a nice finish.
Outside of that I think Mahogany is a good choice for stability. weight. etc. Mesquite is also pretty stable and extremely strong but not the easiest wood to work and it can be quite expensive.
All things considered mahogany is hard to beat.
I have the ANSI standard handy, so if anyone wants some info, send me a PM. The formats listed are:
Has anyone ever considered expanded PVC as a film holder material instead of wood?