The Hill Peg Paste is the best known peg paste, recommended by professionals. It is a composition for temperamental pegs which have ceased to run smoothly.
Use sparingly by putting a small amount where the pegs rub on the pegbox to help them turn more smoothly.
The Hill Peg Paste serves two different (and almost conflicting) purposes. It both 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.
Without the proper amount of friction to hold the peg in place, a tuning peg will tend to slip, making a tuning setting virtually impossible to maintain. String instruments with pegs that are slipping can be tuned briefly, but will be out of tune within minutes as soon as the peg slips again. With too much friction, adjusting the tuning at all is impossible. Tuning pegs that are well fitted and properly coated will both turn smoothly throughout an entire rotation and hold firmly wherever the player wishes.