These posca paint markers have a non-toxic, water-based formula that produces dense, vibrant colours on a variety of surfaces. The markers are permanent on most porous surfaces and are removable when used on glass. The markers have an extra-fine, calibre nib that measures 0.7 Mm. These markers can be used on a variety of surfaces like glass, metal, wood, cardboard, and paper. The ink is non-toxic and has a water-based formula. With the comfortable, round barrel, they are easy to use for long periods. These markers are permanent on most porous surfaces and can be removed from glass. The colours included in this pack are white, black, gold, silver, yellow, pink, orange, red, violet, blue, light blue, green, metallic blue, metallic green, metallic pink, and metallic red. There are 16 markers in this pack. The calibre tip, with a metal ring, has the same qualities as a paint marker in pen form. It is designed for professionals and beginners who require an ultra-fine and consistent line in a wide selection of colours.