After they are dry, press them in a blotter book.
Fiber prints curl, always have and probably always will.
Were you to alternate sheets of corrugated board with
those layers of prints and blotters you'd have the prints
dry and flat in one move. I call it a Corrugated Board
Stack Dryer. Rather than absorbent blotters, sheets
of non-woven water repellent polyester are used.
I sponge dry prior to laying in the prints. Doing
so, I believe, will draw water from a print
leaving it dryer to start. Any flat, clean,
level surface will do
I've posted many times on this subject and in some
detail. As well as the Sticky which covers the subject
search for, corrugated ... posts. Dan