These are designed for fabric. Some of those pens designed (blue) for quilts have their issues. If you get them too hot rather from an iron or leaving them in your hot car it'll set them in. If you don't soak them (most just rinse) they'll come back and if you've ironned in the meantime they may be permanent. If you get them the least bit wet your design is gone which can be a pain. Sometimes I use both depending on what I'm doing. I soak my fabric in water (hot if not the blue pens) sometimes with soap and then iron them when almost dry. Never had a problem

I love the & use them on a lot of my quilts.

A question- I have found the 3 pack of red, blue & black at Staples. Is there a silver or white available for marking on dark fabrics?

See, this is the part that most people think I'm talking about when I say I won't use the pens because those marks don't entirely disappear. I'm not worried about the marks coming back if I send my quilt to the North Pole and it gets cold. I'm worried about the fact that because they come back, there is obviously some ink still on/in the fabric, and nowhere does it say they are acid-free and archival quality! I'd much rather use my Sewline fabric pencil, which is designed specifically for fabric use.

I respectfully disagree. Who told you this? When I found my first Frixion pen 4 or 5 years ago, I did a LOT of research about them. I searched the internet and contacted the manufacturer. They were never designed for fabric. The manufacturer might be marketing them as such NOW, since there's been such chatter about them, but that still doesn't mean they were originally engineered for this purpose and contain acid-free ink.

But, to each her own. If you want to use them in your quilt, by all means do so. As I said, I still prefer to use products that I KNOW are safe.

They have less chemicals in the ink then in the fabric printing process. I use them, even for writing on paper.

I love mine, I did notice a line on the fabric when I had used a black one, but I had left the project several weeks, thought that was why and I haven't washed the project yet, I usually use the red one but am pressing as I go and haven't had any problems.

I just discovered these last week! My friend told me about them, and then we found some at a quilting/sewing garage sale. I used it on a darker batik and did notice a thin line that looked like bleach. It's small and not noticeable unless you know what you are looking for.

I was told by a company rep that they react differently on Batiks versus quilting cottons. BUT - can't remember what the difference is!!! I think the comments about white lines was the reaction on Batiks.

While I am aware of the problems with using Frixion pens, I confess that I use them often, usually on light fabric. So far, I have been pleased. I purchase mine from Staples. I do test them on a scrap of fabric before using them and do not use the on fabric that has a bleach line when heated.