I'm sure you can make one. check the photos on Bostick. they have a good one for sale. good non warping wood and using a tongue and groove when framing would be the best. then finding spring steal to hold the back in place. If you buy new they will last a life time. I have them from 8x10 to 8x20. I use mine for Azo printing and Pt/PD printing.
Good luck if you make one, If you are good with wood you can make some really nice ones.