I have some largish prints that I will exhibit locally. The print sizes are nominal 16x23 and 23x34. I don't really know at what size I should use 8 ply mat board. I have been regularly exhibiting prints up to 16x20 (matted and framed to 20x26) using 4 ply mats and the Neilson standard frames. These look good but I am not sure about going any larger. I might be able to get away with staying with the 4 ply mats for the 16x23 prints but I really doubt that this will work with the 23x34 prints. For these I am considering to use the Neilson Standard plus three frames and 8 ply board. Also what sizes would work for the overall mat and frame dimensions for these print sizes? If anyone who is working in these sizes and is familar with the Neilson frames can give some feedback I would appreciate it. Framing and matting prints at this size is an expensive proposition and I don't want to be in the position of ordering materials that won't work for me. All dimensions are in inches. Thanks in advance. Art