My easel clamps stretched canvas from the
inside of the stretcher bars and doesn't have a place to prop a
mahlstick. I made a mahlstick prop from 1/8" hardboard, drilling
1/2" diameter holes spaced 1" apart along one edge and sawing cuts
in the hardboard on 45-degree tangents to each hole, which I can
clamp onto a stretcher bar anywhere I need it with two small
(see the attached). For a mahlstick, I use a 36"
length of 3/8" brass tubing (with a wall thickness of 0.017") spray-painted black; I found that wooden dowels
and aluminum tubing were too flexible in the thickness I like.