Ox Gall Liquid is a wetting agent, can add flow and extra dynamics to watercolours, which may otherwise be temperamental. It reduces surface tension, meaning that the paper tends to react positively to watercolours without warping.
• A wetting agent used to improve flow when mixed directly with watercolors
• Can also be used on very hard sized papers to reduce surface tension
• Add 3-4 drops per cup of water.