Montana Chalk Spray Paints are ideal for outdoor temporary marking as well as for indoor studio artwork. They are made from high quality eco-friendly chalk-based pigment. Depending on weather conditions and climate, outdoor marking lasts between several days to several weeks. The colour is deep matte, high covering and can be made permanent if desired by sealing with a varnish. These chalk spray paints work well on canvas, wood, walls as well as many other primed grounds due to the great coverage.