A friend wants to make a memory quilt for her granddaughter with a section of the quilt for signatures of friends and family. She questionned me as to what material she might use and how to protect the signatures from smudging or fading during use.

Can anyone help me with this?

Permanent fabric pigma pens work great! You just heat set them.
It helps to iron freezer paper on the back of the fabric, to stabilize it while writing on them. The shiny side is placed on the back side of the fabric. Do not use steam :D:D:D

ditto

I made one several years ago, and had the grandkids each do a square of muslin; backed with the freezer paper. I gave them crayons, and then set them using a brown paper bag and an iron. It worked fine, and has been washed without fading. There are also wonderful fabric pens you can use. She will love it!

My daughters do scrapbooking and purchase a lot of Creative Memories stuff. Their acid free, lignen free pens are permanent on fabric. (I tested them) The metallic set of pens write really nice and easy.

sounds like fun

THIS SOUNDS LIKE A GREAT IDEA AND I HAVE HEARD ABOUT USING CRAYONS AND WOULD LOVE TO TRY THAT WITH MY GRANDBABIES.