My frustration with "hit or miss" corner adherence (if that is a word) has reached the point of asking for help! I used to love MT-5 which adhered under heat; I have a love-hate relationship with the Archival tissue which adheres during the cooling cycle. (I could probably just change to Colormount which I think is also heat-adhering, but at least philosophically I like the archival idea.)

First: equipment - I have a Seal 110s press, which has the 12x15 platten. I'm mounting 11x14 trimmed prints (so they are slightly smaller than the nominal size) which obviously doesn't leave a lot of leeway in placement in the press, but I try to be careful and make sure that the platten covers everything. The problem I'm having is that randomly I get one or more corners not sticking. I've tried a variety of approaches (please bear with me, just trying to provide as much info as may be relevant).

Originally I would sandwich the mount board (2-ply) and tacked print in-between two more pieces of 2-ply, and when I removed the mounted sheet, quickly place it under a heavy glass sheet (since I never owned a proper Seal "iron plate," the 20x20 is currently listed as special order at B&H, $280). I experimented with temperature and time, and no matter what, got inconsistent results.

Since I never had a problem tacking the mount tissue, I thought I would try to see how close I could get to that approach. So I tried taking the top 2-ply off the sandwich and just using a sheet of interleaving tissue between the print and the platten, set the temperature to 175 for about 1'15", and then placed the mounted print under an aluminum baking sheet with filled 1/2 gallon containers as weights. Again, inconsistent results - sometimes good, sometimes the unstuck corners. Admittedly the baking sheet is again just slightly larger than the trimmed print.

So: would appreciate thoughts on technique, and perhaps a better idea for the cooling weight if the problem is that everything is so close to the print size so that placement has become too critical. Admittedly I get good mounted results if I go through multiple cycles for each print (i.e. keep trying until it finally works) but there must be a better way!