Helping Hands Marbling ToolFabric is draped from four corners and dropped onto paints center first--something that's hard to do without four hands. If you're working alone, you'll need to construct a set of helping hands to lower the fabric onto the size.
Cut two dowel pins slightly shorter than the width of the fabric you plan to marble. Use electrical tape to secure a sturdy straight pin at the end of each dowel.
Position pins with sharp tips extending just past the dowel ends, so that you can easily pierce the comers of the fabric to attach it to a dowel.
Once fabric is attached, you can hold on to the dowels instead of the fabric edges, and lower the fabric onto the size in one fluid motion.