Have you ever painted diluted watercolor on a surface and had the paint bead up, or skip areas you intended to have color? This is probably a surface tension issue. Putting a little QoR Synthetic Ox Gall in water used to coat the painting surface and/or to dilute watercolor may help ‘wet out’ hard sized papers and less absorbent surfaces like acrylic gesso or YUPO®. Synthetic Ox Gall contains no binder, and so is an additive rather than a medium. It should not be used full strength.
QoR’s Synthetic Ox Gall can help because it is a wetting agent or surfactant that reduces tension between the diluted paint and the painting’s surface. It also may slow down drying slightly. Synthetic Ox Gall added to the paint or water changes the way watercolor moves. Our starting recommendation for dilution is 2-5 drops of Synthetic Ox Gall to 8 ounces of water. This mixture may increase movement and flow over a wet surface when brushed onto paper, used to dilute paint, or both. Since QoR can be quite lively when painted wet-in-wet, results may be subtle