I tried it on a test piece and the lines came back once they got cold even after the wash. Not sure I would ever use them.

Cindy Needham swears by them but she gives a disclaimer: She ONLY uses them on her own quilts. Sometimes the pen can leave a faint shadow line, so always pre-test. She only uses black and blue as she's had problems with the red and orange. She also recommends marking them so you can easily distinguish them from a regular pen.

I was constantly frustrated, before discovering these pens, trying to mark with chalk or pencil or . . ? I did have trouble with the orange and pink pens, that the marks did not come completely out, but the blue and back are simply marvelous! Sharp, clear markings that disappear with a steam iron.

i read on another forum that if you was in synthrapol the marks come out. I haven't tried it myself, though

I use these pens all the time and find that, if I hover a steam iron over them, they disappear, not to return.

I live in new england and I use the pens all the time. It gets very cold here and I cart quilts all the time to my friends house and I've never had a line reappear after I ironed it out

I ran my own test a couple of years ago. I took about 15 different fabrics and tested the frixion pen on them. I scribbled on them, ironed them them threw them in the washer and dryer. Then I placed them in the freezer. the lines came back faintly on some of them. I re-washed them and put them in the freezer none of the marks came back. I have had the the pen leave a faint line that almost looks like it is lightly bleached after ironing on some darker blues. So far it has always washed out for me.
I have played a little bit with the frixion highlighters. So far I love them for marking multicolor quilts. The will show up on dark and light colors. So far I have had good success. I always test any makking pens I use on scraps before I use it all over a quilt.
Years ago I heavily marked a wall hanging with one of those blue markers that come out with water and had a terrible time getting it out. Lesson learned! Test on scraps first.

Frixion Pen
 

I am in the "have one but don't use" crowd. After reading all the pros and cons on this board and others who have used the pen, I just don't think I want to take the chance. The blue water soluble pen works just fine for me. After marking all over my quilt top for quilting and after the quilt is finished, I simply put it into the washer with cold water and let it soak for at least 20 minutes...DO NOT ADD SOAP during the soaking session...then wash as usual. The blue ALWAYS disappears to never return again. Love the blue pen for marking.

I agree.
 

I love them but like Ariannaquilts I just use where willnot be seen or is cut away later.

I use these pens all the time, instead of an iron I use a hairdryer that way it does not "flatten" the quilting.

i use them all the time, too! Love them. The shadows on darker fabrics go away once it's been washed.