Opacifying Medium will radically opacify transparent and semi-opaque colours without white! Retains the true hue of the colour while providing added hiding power. Hollow acrylic micro-spheres work to scatter the light, creating a dry- hide effect. Milky and translucent when wet, Opacifying medium dries optically opaque and matte. Can be mixed with Tri-Art Acrylic colours in any proportion.