I read several bad commend about this product and thus decided to write one of my own. These pens are really cool if you know how to use them. after writing on any surface, you NEED to blow dry the ink with a HAIR DRYER. The ink is heat-sensitive so that it need to absorb some heat (just like when you bake) to be puffy. I used different brand of these puffy-ink pens and they all give good result. Will recommend them to artistic people who are serious with crafting and such.