It is an erasable gel pen by Pilot, and it is marvelous. You can mark on fabric, then press it, and the mark goes away.

However, there is one word of warning: If you put the fabric in the freezer, the marks reappear. So, to me it's just a little scary.

What if I make someone a quilt and it's freezing cold in their bedroom? Will the marks reappear then?

Oh, that is interesting... wonder what cold water would do to it then, in the wash and you want to hang the quilt to dry?

I'm still skeptical. i bought some but haven't used them yet. perhaps on a wall quilt.

I just washed out the pen markings that came back after I froze the fabric swatch. The next step will be to let it dry out and see if it comes back when I freeze it again. This is interesting.

Thank you for testing this for us :D I will be watching to see what happens next :D:D:D

Definitely interested to hear what happens. Rather you test it and find out and save me the money. Thanks. LOL

Take a piece of fabric and mark it. Put it in a cold bedroom and see if it will come back.

It will be interesting to know if it will.

It did not come back the second time.

Our bedrooms are not that cold in Mississippi.

I'm going to do some more testing.

Thanks for testing these....

Where do you find them?