Find your perfect marking pen

This method only works if you are prepared to wash your quilts in your machine.

First grab a whole load of pens (different colours of the same kind should also be tested). Write the name of each pen on a piece of fabric. Press the marked fabric with a very hot iron (this will set some of the inks) Pin this piece of fabric to an item in a wash with safety pins. I washed mine today on an everyday wash program with my white sheets. This is the same wash cycle as I would wash my quilts (though I do lower the spin speed for heavily quilted items; I don't want permanent creases).
I then put the fabric though the dryer (this is another test to make sure the heat doesn't bring the ink back). I pressed it and you can see the results below.
I was surprised to see the Zebra Antique pen turned out to be the clearest. I shall put this in my drawer of permanent markers as it faired better than the Pigma Micron. Not only is it cheaper but I can buy it locally without having to wait for the next quilt show or driving a couple of hours. It's also a rollerball, so it doesn't drag on the fabric.
I had been using the Berol Handwriting rollerball pens exclusively as these were the best when I first started using them about 10 years ago. It's nice to find I have other options.
This is what works for me. I have heard of one person who had trouble washing out the Berol, but I think she was hand washing. Another friend bought round a quilt for me to wash in my giant washing machine. It washed out of all the fabric (including a white on white) except the white stripes on a yellow and white striped fabric. Very odd, but I'm pleased to say it did wash out on the 2nd wash.
Today's test used Enzyme/biological washing liquid, but I normally wash my quilts in non bio/enzyme liquid so I shall have to run the test again.
I hope this gives you the courage to try pens available in your own countries. The very worst is you shall end up with a nice selection of pens to keep by the phone (grin).