Montana"s Extra Fine (0.7mm) ACRYLIC Paint Markers contain high quality water-based paint made with a high concentration of lightfast pigments that cover well. It is water-proof and abrasion-proof and can be used on almost any surface, indoors and out (though when using outdoors it should be varnished). The paint is safe to use, it is solvent-free, ACMI approved and each marker carries the AP mark of non-toxicity. Each marker features an optimum flow control pump-valve system that allows for accurate handling and application. The body of the marker is transparent so you can easily see if it needs to be refilled. Refills and replacement tips are available separately. The line of Extra Fine ACRYLIC Paint Markers comes in 12 colors that match to corresponding colors in the Montana GOLD spray paint line.