Blue is the workhorse. You're marking up documents, labelling storage, writing on a glass partition, and you need the ink to sit there and not smear when someone's elbow passes over it. The Lumocolor Duo Perm blue handles all of it. Two tips in one body — 0.6 mm for tight annotations, 1.5 mm for headers that people actually see across the room. Dries fast, won't smudge, won't run if it gets a splash. DRY SAFE means no surprise ink stains on your laptop bag. Airplane-safe for the drive up to the site. Ten pens in the box, so the whole team stops fighting over the one good blue
