[header] How to erase old marks off a dry erase board [title] Use rubbing alcohol. [step] Wet a sponge with alcohol and rub it into the stain. Dry the board with a clean, dry cloth. 
Use 99% or 90% isopropyl rubbing alcohol for the best results. [substeps] You can put rubbing alcohol directly on a paper towel or tissue and rub that on the old marks.