If you use wax-based colored pencils or wax pastels and artist crayons, you're familiar with wax bloom, that cloudy, white film that forms on the artwork. Don't wipe it off with a cloth or you'll risk smearing the pigment.

I have a simple solution; just blow warm air over the surface with a hair dryer or a heat gun. If you're not in a hurry, let the heat of the Icarus board do the job for you. When you're done with your drawing, final fixative or varnish will take care of wax bloom for ever.