Typical oil drying agents are derived from ions of cobalt, manganese, and iron, prepared as "salts" of lipophilic carboxylic acids such as naphthenic acids, in order to give them a soap-like chemical formula and make them oil-soluble.
[1] In technical literature, oil drying agents, such as naphthenates, are described as salts, but they are probably also non-ionic coordination complexes with structures similar to basic zinc acetate.
The name refers to "japanning", a term for the use of drying oils as an imitation or substitution for urushiol based Japanese lacquer.
Zinc oxide paints were developed in parallel with the introduction of "oil soluble driers" or "terebines" around 1885.
Terebines had poor shelf life in mixed paints, as they auto-oxidised and lost their effectiveness.