I make the shawls, but I often use the fleece and double knit fabric that has been donated to me and which I have no other use for. In this case, I piece the double knits into scrappy squares or D9Ps and then stitch them right sides together to the fleece. This combo makes a really warm shawl and uses up those double knits.
I get fleece remnants when the fleece is on sale at Joann's so it's on sale then also half price on the remnant. If one piece is too small, you can combine two.