Hi Wayne - The Japanese material was offered by one Aki-Asahi at aki-asahi.com. I found the thickness to be no problem. I measured it myself and it was extremely close in thickness to the Graflex fabric in my camera. If memory serves both were bang-on at 0.008 inches. The actual
avoirdupois weight per area of the Aki-Asahi (AA) was greater than the Graflex stuff, but that did not create any problems. In short, it works.
I believe there are now two varieties of AA material. One is rubber-coated fabric and the other is a sandwich with fabric on the outside and rubber in the middle. I am only guessing that the tri-layer is thicker than the bi-layer but this is pure speculation - I have never handled the tri-layer.
Incidentally, the AA fabric oozes quality and happens to be gorgeous. It drapes beautifully, has bombproof opacity and is possessed of a lovely hand as well.
Hope that helps a bit.
Jon
Has anyone found curtain material that will work? Last I read a few years back was that there was something out of Japan I believe, but I think the thickness was a little more then what was used in the OEM stuff.