I have a Fujimoto G70 which I enjoy using for my enlarging; however, the negative holders are non-glass. As in, they flip open, you place the negative in the open space, flip close using the metal edge to hold the negative in place and insert. This is not normally a problem with 35mm negatives but yesterday I was having serious problems getting a 6x7 negative flat. I could get some of the negative in focus but not all and the problem increased as the lamp warmed up and the negative began to buckle. Can I just buy some small pieces of glass to sandwich the negative and then insert into my current holders or do I need to purchase new holders? The Fujimoto was never exceptionally popular and holders are hard to come by. I have tried using Omega holders but with very limited success. The biggest problem is the holder slot is square and using a round holder does not allow me to fully insert into the space in order to cover the larger negatives.