But I have also read people who have washed and it DOES come out. So I guess there are different results from washing.

yep...and since it is a CHEMICAL in the fibers, you never know what other chemical will hit it and make it reappear in the future!

That's a good point too. Chemical reactions to other chemicals are unpredictable.

Yes, the air soluable one are still there and sometimes they do show up again after you wash them or iron over them. Even with the blue ones that are supposed to wash out, I have had them show up again too. One thing I was told later was to NEVER iron over either the air or water soluable pens. Live and learn.

I marked all over a white cotton tone on tone with every color of the pens I have in the set. I didn't iron it. I washed the fabric in a load of towels and dried it with the towels in the dryer. I put it in the freezer (sub 0) over night. No marks appeared. I am sure the ink washed out.

I used one to do some markings. Ironed it, lines disappeared. I put it in the freezer overnight and nothing reappeared.

I believe an important word in Charlotte's test is "the ink is always in the fabric". Even if it disappears it is still there and who knows what might happen in the future to bring it out other than the cold. This is the same with the purple disappearing ink fabric marking pen. Even after it disappears the chemical is still in the fabric.

Most of the time, I just use a #2 pencil and mark light enough that i can see the lines. After hand quilting the quilt, most of the pencil has rubbed off. I do like this Frixion pen for darker fabrics that i can't see pencil lines.

I like a good old fashioned graphite pencil... lightly marked...

That sounds great. Thanks for the info on your test. I feel much better. A quilt teacher of mine who has always been extremely careful about marking her quilts swears by these pens.