Marked balls, training cue balls and flat position markers make drills measurable, but every object touches the cloth. Use equipment approved for the table surface.
Marked balls
Visual marks reveal post-contact rotation and help assess strike quality. The finish must be smooth; remove any ball with a burr or chip before it scratches cloth.
Position markers
Use thin flat discs or purpose-made stickers that leave no adhesive. Thick tokens under a ball change its level and can damage the fabric.
A repeatable drill
Mark the cue-ball start and target zone, repeat the same stroke, then remove markers before rolling balls across them. Record accuracy, speed and dispersion rather than pots alone.
Inspect the bed after practice and wipe accessories with a soft cloth.