Provides straight corners. Flexible enough to use over irregular surfaces. Plaster keys near the nose to give reinforcement where it is needed most. orner Bead have a smooth round nose bead with Diamond Mesh wings for the keying of plaster right up to the nose of the bead. On the outside is the finished edge which is where one side of your drywall knife runs on when you are applying drywall mud. The two flanges sit flat on your raw drywall. The diamond decoration along the length of the flange act as a keyway for holding the drywall....