I have a friend whose nephew was born blind. Her idea for doing this very same thing is to use several different fabrics with various textures, bumps, weaves, etc. When I have been out & found remnants that would work, I have picked them up for her. One I found was left over from Halloween & had raised spider webs. Another had "bumps/nubs" on the fabric.
I'm not sure if she's made it for him yet, but it should turn out to be very tactile...