Suz, I too discovered the invisible pen. That's what I thought it was at first. It doesn't seem to last long but it is the only thing I found to work. The chalk brushes away before I'm finished and I can't sharpen those waxy pencils because they always break. This pen with liquid ink is the way to go.
kathy
( I think Clover should send us some coupons or something because they get a lot of free adertising on this board.) LOL