Create confident and razor sharp lines with Avery Marks-A-Lot ultra fine markers. Thin but also sturdy, the 0.5 mm marker tip stays solid and does not fray over time. The versatile, permanent marker ink dries quickly when used but won't dry out if you forget the cap. Leave the cap off for up to half an hour and you will still be able to pick the marker back up and keep writing. The permanent ink resists wear and water exposure and is perfect for any project. These markers work with almost any surface including paper, cardboard, metal, PVC, concrete, plastic and ceramic. Whether it's your bullet journal, planner, water bottle or phone case, these ultra fine permanent markers can go wherever you need them. Avery Marks-A-Lot permanent markers are also low-odor and nontoxic so that they can be safe in the classroom, the home, or even in laboratories. The ink is ACMI certified as nontoxic and conforms to ASTM D4236.