Thanks Dave,
I have the same size Seal dry mount press that you have. I have the older version and it works like new and is built like a tank. I use it for flattening prints.
I will try doing a test of 30x40 print on Platine using the Seal Dry Mount tissue. I realize the Color Mount can be used for fiber papers, but wasn't it designed for rc media with a lower heat melting point? I used to use the Seal MT5 for my dry mounting of silver prints back in the mid 70s and wouldn't you know it, not a singe one has delaminated or stained the edges of the prints. They are perfect. As are Ansels portfolios at the Center For Creative Photography in Tucson. And I have moved them from 4 different states and climates. Seal Good.
I also used to use a dry mount tissue called Ademco. Now that stuff was like the old original Seal tissue. It was clear as apposed to yellowish like the later Seal tissues were. I used the Ademco because it was used by major framers ( at the time ) for doing multi-dimensional mounting, like dry mounting one board to another, and actually dry mounting prints to other prints, etc. Now with that stuff once it was down, it was down. No putting it under high heat and peeling the print off. I will never come up. I'm going to check to see if it is still available. My old prints from 1976 still look perfect, but then so do the seal mt5 prints. I only used Color Mount for color c prints and they are still mounted too, just faded like hell.
I'm going to get back into thermo plastic dry mounting for my pieces that are going into shadow boxes. I miss doing that. I wish I had a press that would do 40x60s but that isn't going to happen. Even if they made one I couldn't afford it. I'm also wanting to mount to 4 ply rag board and then glue that to aluminum with polyvinyl acetate glue. I still don't trust that vacuum press stuff for the very long term of my carbon pigment prints. It seems to me that as long as it has been around someone should have provided us data about it's longevity. I've also seen many cases where the vacuum mount prints have delaminated. That's not good.
john