Rosin
From London's Ghost Acres
Rosin, also called colophony or Greek pitch (Latin: pix græca), is a solid form of resin obtained from pines and some other plants, mostly conifers, produced by heating fresh liquid resin to vaporize the volatile liquid terpene components. Used to manufacture printing inks and as a flux for soldering.
https://en.wikipedia.org/wiki/Rosin