American Crafts-Erasable Chalk Marker: Black And White. These markers are perfect for use on chalk boards, windows, mirrors, ceramics and more! They are erasable with a damp cloth. This package contains two 5 inch long chalk markers in assorted colors. Conforms to ASTM D4236. WARNING: This product contains chemicals known to the State of California to cause cancer, birth defects or other reproductive harm. Do not mouth or chew. Imported.