There are situations in which the Pilot FriXion pen ink will not wash out. See:

http://quiltingclimber.blogspot.com/...evaluated.html

Please note that she only did a few tests. You should always experiment with your starch, etc on your fabric and your water, etc.

you were lucky it didn't fall into the wrong hands

Another vote for the Pilot FriXion pens! Magic!

These are what I also use as I have to use polyester batting and you can't iron it. I have never had a problem but I only do a small area at a time.

I use the blue mark b gone that comes out in water, but not on pink fabrics. It will leave a mark on pink.
I also use the purple air erase markers and have not ever had a problem with them. I don't always quilt fast enough and have to remark sometimes.

I have used the washable markers by crayola, they made a nice bright line but one of the colors did not come out, it left a shadow where I quilted - I don't remember which color.

I have had a problem with the blue chaco markers not coming out of fabrics so I don't use them now.

Pilot FriXion Pens are my new BF!!!! I Love them and they dont leave a mark!

Yes, I love them. Just make sure if you don't get to your project immediately, that it isn't under a fluorescent light, because it will disappear within a couple hours.

I have used the Mark B Gone pens when making garments where I might be marking something that will be hidden in the seam anyway. I have been tempted to mark on the quilt top but have been afraid that the marks would not be gone.

I tried the washable Crayola markers, also. The color I used left a yellow line. I probably left it on too long.

I've had good luck swith Frixion pens. Someone mentioned yellow. Haven't seen that yet but I've been hoping they come out with a light color. I'm going to a quilt show today and will be on the lookout.