Here are the latest solid model renders of the holders. Another couple days’ work and the design will be shared with the mold maker for final review and feedback.
I also have some weight information, approximate at this time but fair to accurate to within +/-10%:
8x10 holder: 230g empty. 600g loaded with 2 plates
5x7 holder: 110g empty. 267g loaded with 2 plates
4x5 holder: 71g empty. 160g loaded with 2 plates
Despite the light weight, the design of the holders ensure the rigidity necessary for photography. It’ll just be easier on our backs/shoulders.