When you're painting sisal, remember that it is very porous and absorbs paint well. Apply paint thickly, taking your time, and apply a second coat if necessary for complete coverage. When working with sisal, don't blot paint onto paper towels as you ordinarily do in stenciling. Instead, use a lot of paint and work it thoroughly into the fibers. You can go back over a stenciled area after it dries and add darker tones to give greater depth to the design.
Sisal rugs have a border on the ends that can be painted or left their natural tone.
Be sure to use a pad under your painted sisal rug.