Winsor and Newton Professional Acrylic Flow Improver is an effect medium that maintains no colour shift from wet to dry when used with Artists' Acrylic. It is a fluid that can greatly improve the flow, absorption and blending of acrylic paint. It increases the looseness, allowing the artist to apply areas of flat colour evenly without changing the colour strength. Professional Acrylic Flow Improver can also minimise brush marks by reducing friction of paint application, ensuring your paint is applied smoothly for a great finish.