Matisse Fluid Acrylics have a very smooth, runny but slightly dense viscosity. Being highly pigmented, the colours will appear dark and intense on initial application but can be spread easily with a brush or mixed with water to reveal the colour graduation. The intensity of the colour is what makes Matisse Fluid ideal for tinting. The consistency allows precise drop-by-drop addition to any of the Matisse range of acrylic paints and the precise ratio of tint to paint can be easily replicated. Each colour has an ASTM rating of I or II indicating very good lightfastness to excellent lightfastness and are completely opaque when used directly from the container. Matisse Fluid is completely compatible with Matisse Structure and Flow formula paints, can be either blended together or used by itself on the same artwork.