We recommend Posterman, Illumigraph & Woodcraft for use on glass surfaces and windows. All of our glass pens are perfect for use on tiles, and windows. Available in a choice of waterproof and wet-wipe for use internally and externally. Use our waterproof glass pens outside and remove the ink with our EaziKleen Pen Remover. Need glass pen advice? Call 0161 763 1072 we will be happy to help!