There are many different packing materials which can be used with a drying machine. The packing material retrains the paper while allowing the air to flow so that the moisture can be removed. Some experimentation is required as to which material will work best for a given paper or art being dried. The following are recommendations which can be sued as guide line
Packing Materials for Flat Sheets; Standard Pack Materials
The Standard pack material for flat sheets is the "Screen Sandwich"
The Screen Sandwich is made up of 3 materials layered on top of each other, in this order:
Second layer is a flat smooth mesh designed to keep the paper flat and free from buckling
First layer (bottom layer) is a stiff 3d mesh designed to allow the air to circulate