A spine bookcase is designed to hold stacked bookcases in a vertical line on the wall so that when the bookcase is full of books, the bookcase more or less disappears. Spine bookcases are often expensive and sometimes hard to come by. Making your own will work out cheaper in most cases and is a job most do-it-yourselfers can handle.
Measure 12 inches from the end of the 72-inch plank of 2-by-4 lumber and mark a line across. Measure and mark every 6 inches along the plank from the first 12-inch mark.
Place the plank, which is the spine of the bookcase, upright on the wall where you want to hang it along a wall stud. Use a stud finder to find the wall studs. The end with the 12-inch mark should be pointed toward the floor.
Secure the plank to the wall stud with two 4-inch screws. The screw must be driven 2 inches in from each end of the spine, as well as 2 inches through the center of the spine.
Place two L-brackets on the 12-inch line marked on the spine, with the horizontal arm of the brackets even with the line. Position the brackets so that they are flush with the sides of the spine. Secure with 1 5/8-inch screws through the screw holes of the L-brackets.
Repeat on all the lines marked along the spine to finish the spine bookcase. Once the bookcase is filled with horizontally-stacked books, you won't be able to see the L-brackets or most of the bookcase spine.