The creation of Fluid Chalk was inspired by the Chalk Pastels and used by the world's finest artists for centuries. The warm and complete palette of soft colors share the resilience of pigment ink yet they stamp and blend like dye inks. Inks dry quickly on most absorbent surfaces and become permanent when heat set. They resist smearing, bleeding, or fading even when air dried. The very flat, muted finish lends itself to many simple, sophisticated looking techniques. Most effective on coated paper. These chalks are also acid-free.