Archival fast evaporating odourless lean medium behaves in the same way as regular odourless lean medium except that it evaporates rapidly and dries even quicker than traditional turpentine. A general purpose, alkyd resin medium. It feels oily, but dries with a low sheen. Increases flow and transparency, and the surface of a painting can be worked during a full day without tacking up provided the canvas is well sealed. Do not use as a finishing varnish. May thicken and become unusable if stored in a bottle with a large air gap at the top. To avoid, decant into smaller air tight bottles.