skin marker: used in radiology research and doctor use, marking on patientsf skins before surgical and skin disease treatments! ink is nontoxic and nonirritant! clear and safe use on skins! regular color: violet. nib size: 1.0 mm. nib 0.8 mm/0.5 mm and other size can be offered by order production! attentions: 1a clean and dry the skin firstly, and then use the skin marker for drawing! 2ause iodophor to disinfect the skin and fix markings! 3ause the dilute alcohol to remove the markings! 4adonot use a same marker with different person to avoid possible infection! 5acautiously use on mucous membrane or wounded skins; please test with the patient who are sensitive to gentian violeti