I have used those in a pinch for a long time myself, I only have trouble with the yellow(as mentioned) and the orange ones. I just finished a quilt that had been marked with yellow, orange, and blue highlighters 4 yrs ago(I prefer these since they are the same size as a pen). After making a "solution" of a quarter cup of powdered laundry soap(Purex) and a bowl of warm water, I used a soft hand cleaning brush to apply it to the marks. I was just so sure they would never come out so I freaked and pre-soaked them, just in case. I must say, I was impressed as all the marks came out on the first wash! Even the orange marks. I had ironed, steamed, re-marked and left those marks in all this time and still got them out. I agree with the one(s) that mentioned the artists pencils as well, I have yet to have a problem getting them out either.

I read an interesting thing about these pens...The ink disappears, but if the temperature of the quilt is exposed to 32 degrees or less, the ink re-appears. I have never used these pens and tried this experiment, but a friend told me this will happen. Maybe you just shouldn't take the quilt to any outiside winter activities...?

I use soap slivers to mark my quilts. Being soap, it always "comes out in the wash" ! :) Of course, it's obvious this method works better on medium to dark fabrics.

This sounds good, but one day my grandson left a washable marker on a large white dish towel and it bled out on the towel. My daughter said not to worry it would come out. as soon as they left I washed it and it did not all come out, and as long as I had it you see a blue spot on it. Not to be a downer, You might want to try it on scraps first. You have so much work in quilts to have a spot on it. And yes it was a washable pen.

Thank you, good to know

I use parchment paper, baking paper, for my stencils that I quilt onto my quilts. It does rip easily and leaves the stitching intact plus it can be found relatively easily in the baking aisle at the grocery store. I hope this helps you.