Peg dope

"Peg dope" (also peg paste, peg stick, peg compound) is a substance used to coat the bearing surfaces of the tuning pegs of string instruments (mainly violins, cellos, violas). Manufactured varieties are generally sold in either a small stick (resembling lipstick), a block (like rosin), or as a liquid in a bottle. A common, but less effective homemade recipe is a mixture of soap and chalk. It serves two different, almost conflicting purposes. It lubricates the peg shaft so it turns easily in the pegbox, and provides friction to keep the pegs from slipping with the force of string tension.

When pegs slip, tuning can become virtually impossible. Afflicted violins can be tuned, but within minutes the instrument can be out of tune again. When pegs stick, tuning is very difficult or impossible. In between these extremes, one may find pegs that tend to slip unless firmly seated, or that do not turn smoothly, alternately sticking and turning. Well fitted pegs, properly doped, turn smoothly and hold firmly as the player wishes.