The Schneider Paint-It 320 Acrylic Markers feature exceptionally high-opacity, full coverage, and high-color brilliance. Good for indoor and outdoor use due to water-based, almost odorless ink. Bullet tip line width approximately 4 mm. Ink color assortment in a wallet of six (6) includes one each of Black, White, Blue, Violet, Red and Green. Cap color indicates ink color. Fast-drying, valve-controlled ink for creative work. Shake the marker, remove the cap, and activate it by pushing (pumping) the writing tip onto a solid surface. Best results and optimized on non-absorbent surfaces. Suitable for use with many materials including glass, wood, metal, plastic, porcelain, stone, cardboard, paper, and more. To ensure longevity, store horizontally.