I attended a Ricky Tims-Alex Anderson seminar. Alex Anderson said do not use the Frixxion pens under any circumstances!

I did a marking demo at my quilt guild several years ago. I cut a piece of about 20 different fabrics. Batiks, white on white, civil war etc. I marked them with all different kinds of marking methods. I used frixion pens in a couple of colors, crayola markers in several colors and a bunch of other types. I did 2 rows of each kind of marking method. One row I ironed over and one I didn't. I then ran it all thru the washing machine. I then put it all in the freezer. On about half of my fabrics the Frizion did not reappear, on the rest it was lighter. After a couple of washes it all seemed to come out for me. I did find that with all of the things I tried, anything blue seemed to be the hardest to remove.

I should have put the quilt in the freezer but my freezer would not have been big enough. I wanted everyone to know washing and drying in the dryer did not set the fixion pens. Thank goodness for that.

I use the pen all the time. Iron wash dry freeze whatever. Never bothered me.