Bob explains how the blue board is attached, shows how the cornerbead is attached, and talks about factory edge seams. Bob interviews Carlos Londono, a plastering contractor, who shows how to apply a veneer coat of plaster over blue board.

When choosing wallboard, remember the difference between drywall and blue board. Drywall panels are covered with paper that will take paint directly once they've been taped and the joints and fasteners have been covered with compound. Blue board's more absorbent paper layer is designed to bond with a veneer plaster coating before it is painted.

Bob meets up with Bill Reid of US Gypsum in the barn of the Medford project. Bill differentiates imperial board (blue board) which is skim coated from drywall (gypsum panels) where the joints are taped. In 2000 US Gypsum developed a new core technology that makes the boards stronger and lighter - for easier handling, cutting, and scoring. The screw spacing is 12 inches on center with the screws flush with the paper providing a good, solid adherence to the wall with the screws. The face paper is treated and absorbent to take the veneer plaster and create the bond. These new boards snap cleanly on the ends. The installer puts a back cut on the edge so that the back of the sheet doesn't hit before the front does. The blue board and skimcoat application is typically not a do-it-yourself project. Traditional plaster jobs were very cost prohibitive so, when veneer plasters came along, they became very popular as they give a much more monolithic look than gypsum panels while providing an abuse resistant finish. Upstairs in the studio the homeowner has specified blue board with veneer plaster and downstairs, where he wants the option to tack artwork to the wall, he has specified a traditional drywall and tape application.