Resin bag or rosin bag?

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ros·in ( P ) Pronunciation Key (rzn)
n.
A translucent yellowish to dark brown resin derived from the stumps or sap of various pine trees and used to increase sliding friction, as on the bows of certain stringed instruments, and to manufacture a wide variety of products including varnishes, inks, linoleum, adhesives, and soldering compounds.

tr.v. ros·ined, ros·in·ing, ros·ins
To coat or rub with rosin.





res·in ( P ) Pronunciation Key (rzn)
n.
Any of numerous clear to translucent yellow or brown, solid or semisolid, viscous substances of plant origin, such as copal, rosin, and amber, used principally in lacquers, varnishes, inks, adhesives, synthetic plastics, and pharmaceuticals.
Any of numerous physically similar polymerized synthetics or chemically modified natural resins including thermoplastic materials such as polyvinyl, polystyrene, and polyethylene and thermosetting materials such as polyesters, epoxies, and silicones that are used with fillers, stabilizers, pigments, and other components to form plastics.

tr.v. res·ined, res·in·ing, res·ines
To treat or rub with resin.





I've always seen it resin, but looks like both are correct.

 

This thread resinates.