I love these chalk markers because they are so easy to clean up.I got them here http://www.amazon.com/LINKYO-Reversible-Replacement-whiteboard-non-porous/dp/B00XKFAJ6W. I got these for my daughter and her cousins to play with when they come over. We have a glass table in the living room and they love taking these and drawing funny pictures on the table with them. When they are done playing, I tell them to clean it up because all you need is a damp rag and you can wipe it off with ease. You can also have the kids write on windows with these. It goes on smooth and easy. You get 10 bright neon colors that all look great on glass. The instructions were simple and straight forward. I would recommend these cool chalk markers because it’s a great way to let your kids express the artistic side of them with this unique set. I received this product for free in exchange for my honest and unbiased review.