I made a label for a quilt for DH back in 2005. I used Micron pigment pens on plain white cotton. It has been dragged around the house ever since and has been washed many times. The key was to heat set the drawings/writing: just used the cotton setting on my iron (steam is optional). OBTW, there is no special fabric treatment required - just write iron and use. Good luck.

If the markers are Fabric Markers you should just have to heat set them with an iron or throw them in the dryer, I use the iron. then they should be good to go. I have labels on quilts that have been washed and washed and still readable and have not faded . Maybe do a test on same type of fabric and pens and see what your outcome is ....Good luck with either a quilt or wall hanging....