Advice For Drying Stamps So They Are Completely Flat?

I am not that big into soaking stamps off paper but recently I had a nice pile of higher value stamps on paper to soak, so I did, and after I had left them to dry on a clean towel, I placed them into an old textbook I had lying around, stacked a few more heavy books on top, and left them for about two days to finish drying. Much to my disappointment, when I went to take them out, I discovered that the stamps were all mildly wrinkled. The moisture from the stamps had caused the paper in the book to curl which transfered over to the stamps. Now to get them perfectly flat I'll have to resoak them all again

Any advice for drying stamps so they are completely flat? Is there a certain type of paper stock to use which you would advise is the best? I also seem to remember seeing a sort of stamp press that had a handle and two heated flat metal plates for drying stamps quickly, does anyone know who makes this or where I can find one online? I seem to remember it being expensive $200-300 but honestly after an experience like this I'm almost inclined to splurge for one.