Romnipotent
First Post
Non Acetone nail polish remover maybe, I use a Terry Whites chemist brand (australia) for plastic miniatures and paint and its perfect.... the problem with removing stains is that you have two colour agents, each has a chemical base, and that chemical base is disturbed and broken apart by a corresponding chemical. You may be able to call the pen manufacturer and find out the basic "ingredients" to their red marker... then find a university college lab and ask them what breaks apart that red compound. 
option Ê would be to match the colour of the mat with a marker, and colour it in...
				
			option Ê would be to match the colour of the mat with a marker, and colour it in...