I have a fair collection of these. I tried to use the white for a French pedicure but it doesn't stay on very well. However, I give them a 5 star review because they are EXCELLENT as a semi-permanent marker. I use them to mark on metal: As an IT contractor, I labeled ports with them, wrote the pc name or department on the back of the pc, labeled the ends of cables, labeled the fronts of servers in a rack, wrote my name on my tools and equipment, IP addresses on the bottom of routers and printers, and now that I'm retired, I've even used it to mark the positions on my cello fingerboard (don't do this on an expensive cello, of course! Mine's a starter model).If you need to label a black surface, use white. White surface, use black. Other colors, use the color opposite on the color wheel for maximum contrast. Can't beat them!And while we're on the subject of things a girl geek thinks to use that boy geeks might not know about: a cosmetic brush works wonders getting gunk out of keyboards and mice, dusting off circuit boards, etc. and a small compact mirror helps in locating things behind desks.Very pretty color and very simple to use. It's just like writing with a pen. Makes nail art that much easier.thank youJust as described and really fast shippinggirls love these pens