If using a clamp, it would seem that there is a 'right amount' of pressure. Just after the clamp has made contact with the record, and then touched the record to the platter. That would be at least reference or starting point for how much pressure is the right amount. Concerning the copper mat, I like the idea behind it. Are these copper 'plates' thick or thin? Do they have substantial weight, and of course, can you be sure that they are flat?
