I just checked out this new to me gel pen. You write directly on your fabric. I would use this with a light box to trace an embroidery pattern.
Here is the same view. It is completely gone! Like magic. This was just a test. I will try it on my next embroidery project. I love the sharp fine line it makes. I usually use the blue markers that you spray with water for the ink to disappear, but there's alot of dripping and rewetting. I think this might do the trick.