9x12 holders with film sheaths do come up, I was frustrated for a while, but then found 12 very good Kodak ones. I love my 9x12 camera, 4 different lenses + Rada roll film back
and masks for 6x4.5, 6x6 and 6x9, it's a really wonderful system. Sometimes I miss the squarer 4x5 format, but 9x12 is very elegant. I like the ground glass and find that I take more time
for fotos and am happier with the results.