I LOVE it! They just do the base coat in whatever color you like, then paint on the white tip, and then do a topcoat, I presume. The place I've been going to lately has a different method, though, that I don't know would work with the dark colors. They do a slapdash stripe of the white tip and then they take a big, soft brush, dip it in nailpolish remover, and then use that in an arc-like motion to wipe off the excess. Then they do the topcoat in clear or very translucent pink. I was totally dumbstruck the first time I saw this, but it makes for the cleanest, neatest "smile" of white I've ever seen. (Too bad it only lasts for like... a day.)