I'm not familiar with the M670, but my Durst DA900, also a 6x7 (or more) enlarger, does come with both single- and double-glass carriers. Is it completely out of the question that they make a double-glass carrier for the M670? Otherwise, what about filing out a lower support plate from a piece of thin, soft aluminum? I think it would hold the negative flatter than cardboard, and could be thinner, making it easier to fit into the carrier.(posted 8506 days ago)