As we were having so many opinions wrote to Pilot about Frixion pens here is the reply.i did say I was passing information on.
Thank your for your email. Yes we do recommend them for use on fabric.
FriXion ink “erases” due to Pilot’s exclusive thermo-sensitive ink technology.
The thermo-sensitive ink turns invisible when it is heated. Normally this is through the rubbing action with the pen (this is how it ‘erases’) but any form of heat will turn the ink invisible, including hot radiators, irons and hot sunlight instance.
The ink will only return if it is exposed to extreme temperatures of around -12 degrees and unfortunately there is nothing that can be done to prevent this.
If your quilt is exposed to this kind to temperature and the ink does return, you would need to simply iron the quilt work or put it on a radiator and the ink will again disappear.
Also, as the ink is water based and not permanent washing the quilt on a couple of occasions is likely to remove the ink anyway
Below I have included a diagram which explains the process
I hope this helps.
Last edited by DOTTYMO; 08-13-2015 at 09:58 PM.