High ratio of oil to resin in a medium. (1) Long oil alkyd – an alkyd resin containing more than 60% of oil as a modifying agent. (2) Long oil varnish – an oleoresinous varnish, other than alkyd, containing more than 25 gal of oil per 100 lb of resin. A long oil varnish is usually slower drying, tougher and more elastic than a short oil varnish. See also Short Oil Varnish and Medium Oil Varnish.