Minimum value for united inches is 12 in. Maximum depth is 20 in. United inches are rounded up to the nearest even number. Measurements are from inside the case “exact.” Standard wall frames are made with 1/4" sides and 3/16" face. Case Dimensions Standard wall frames include our Superior Solvent Seams (nearly bubble free). Museum wall frames are made with 1/4" sides and 1/4" face. Museum wall frames include “The Edge” PS-30 Museum Seams (bubble free). Finished edges include: beveled, rounded and square. Clear acrylic backs or strainers are 1" in depth.