Kathy I think if the marker is Alcohol based paint it will evaporate from the shell in the bator, but if the Marker is water based paint with the humidity of the bator it can penetrate the shell. I whould put anoter test to see if there is a diferent betwee this 2 brands.Yes, and to see if any of the black leaches through. -KathyTo see if marker pens kill embryos?