Ah... these are called "Scotch Tape Rays". Under the black is another coat of sparkle green. Remove tape ASAP after top color is painted and VOILA, perfect lines.
check out the full blog post to see all the pictures!! :)
1)Paint your nails with base coat and then a color. 2)Cut out ten pieces of newspaper big enough to cover each one of your nails. 3) Pour a tiny bit of surgical spirit into an dish and then dip your fingers in it, one at a time.