... metal tape-on corners, corner tape with metal strip, metal reinforced corner tape, corner mesh with PVC profile, paper drywall ... corners which are 90 degrees or not 90 degrees, for manual application only. For example: Archways, curves, vaulted ceilings, coffered ceilings, ... galvanized steel strips act as a guide to ensure straight, reinforced angles for both "inside" and "outside" corner needs.