The I•Semble Shelf Blocks from Rockler are designed to be just as easy to use in constructing do-it-yourself furniture as the traditional milk cases of a college student -- but sturdier, and more attractive. Made of steel with black powder-coat finish and a classic cross design within their bracketed shape, the I-Semble Shelf Blocks can support shelving spans of up to 36" of standard 3/4" lumber. They come with screws, to be used for fastening the sturdy columns the I-Semble Shelf Blocks create between shelves or countertops: no joinery skills required. The I-Semble Shelf Blocks (item 47512) can create bookshelves, desks, entertainment centers and more. They're sold in pairs for $19.99.