I have a tough time with this too. I've bought too many to count of the air erasable and water erasable pens, and if they are not totally dried out when I open them they seem to be good for only one or two uses. I've used the chalk pens, and like them, but sometimes they don't completely wash out. Right now I'm struggling with how to mark a T-shirt quilt that has pictures I printed onto fabric incorporated in it. Those are dry clean only and I'm afraid if I mark the quilt binding the marks won't wipe or blot off. I'm just finally starting to develop my FMQ skills, but don't want to try them on this quilt, as it is being made for a friend. I'll be watching this thread to see what other folks use.