Hi, these can be useful to dry fiber paper flat (not needed for RC paper, as it doesn't curl.)
I had problems when drying glossy fiber paper face down against the plate. The paper stuck to the plate. Apparently using a hardening fixer may help avoid the sticking. Advise not drying face up against the cloth, as dust and other stuff can get embedded in the paper emulsion.
Jon
edit: disregard my comment, I had a different kind, with a metal plate