A slab door is a simple, unadorned door that lacks a frame. It is the obligation of the do-it-yourselfers or installers to attach the slab door to an existing door frame or to build a new door frame. The word "slab" comes from the fact that these doors are made out of flat pieces of wood or metal that are glued together. There are two types of slab doors: full and partial. Full slab doors are whole units that include the lintel over the opening. Partial slab doors only cover the actual door frame and leave the lintel over the opening exposed. Because full slab doors cannot be divided into sections, they are more difficult to install and take up more space when closed than partial doors. However, they are more secure because there is no way for anyone to see what's on the other side of the door if they try to break in. Partial slab doors can be divided into three main categories: flush-mounted, embedded-mounted, and framed-out. In all cases, the lintel over the opening is left exposed. Flush-mounted partial slabs look like ordinary doors but instead of having a frame around them, they have a channel where a piece of molding can be fitted. These can be installed with the molding attached to the wall or detached and placed on a shelf or bracket.