Forget metal. Sheetrock paper-faced plastic corner bead is more durable and easier to handle because it’s 25 percent lighter. Made with a paper tape laminated to a composite plastic that creates crack- and chip-resistant corners, the product is rust-proof and easy to install. It also offers excellent adhesion to a variety of finishes. Cost: $2.80 to $3.20 for an 8-foot stick.USG Corp. 800-950-3839. www.usg.com.