Williams & Heintz Map offers the POD Charts on two durable kinds of paper — 24 lb. JCP E-20 High Wet Strength Map Paper, a white paper with a lithographic finish that is made to be used out in the elements. This economical paper is fully functional even when wet. 36 lb. JCP E-50 Chart Paper, genuine 50% cotton nautical chart paper, the same kind of paper as the lithographically printed charts that mariners are accustomed to. While not water resistant, this special surface can be drawn on and erased again and again.