I tried the flannel backed vinyl and found that things didn't stick up there for very long on their own.
Then tried flannelette by itself.
Then a piece of fleece. Best Ever!
Then, went whole hog, with a permanent design wall. 7.5'x10' covered in black fleece. Before Christmas, I finished a 50"x70" quilt and left it on the wall for over two weeks before it was quilted. Never budged!! :)
I didn't go white, for the reason I knew it would look grungy with time. Plus, I believe black gives a better non-judgmental background. Due to the permanency, there'll be no washing ... though I do run the lint roller over mine, periodically.