I don't know about something that can be rolled up when not in use, like Baysidegal said, flannel is one thing I have heard of.
My hubby made mine using foam insulation board, in addition to using it as a design board, I also use it to spray baste my quilts...we used four of the 4x8 sheets...I love how it works for me! As big as it is it does take up a lot of one wall, but I have the room for it...
Good luck to you,
Kif