I draw and paint on fabric all the time. I use fabric paints & markers, regular crayons and oil crayons, acrylics with fabric medium, even painting with dyes...some techniques work much better than others. It seems like acrylics with medium result in the 'stiffest' , least comfy fabric for a quilt. I would not use canvas, because it does not wash well. I think you would have problems with the paint 'cracking' and, it would be very stiff & uncomfortable to sleep under. Good luck with whatever you decide to do.
