Principal types of binding are padding, perfect, spiral, comb, sewn, clasp, disc, and pressure, some of which can be combined. Binding methods can affect whether a notebook can lie flat when open and whether the pages are likely to remain attached. The cover material is usually distinct from the writing surface material, more durable, more decorative, and more firmly attached. It also is stiffer than the pages, even taken together. Cover materials should not contribute to damage or discomfort.
It is frequently cheaper to purchase notebooks that are spiral-bound, meaning that a spiral of wire is looped through large perforations at the top or side of the page. Other bound notebooks are available that use glue to hold the pages together; this process is "padding". Today, it is common for pages in such notebooks to include a thin line of perforations that make it easier to tear out the page. Spiral-bound pages can be torn out, but frequently leave thin scraggly strips from the small amount of paper that is within the spiral, as well as an uneven rip along the top of the torn-out page. Hard-bound notebooks include a sewn spine, and the pages are not easily removed. Some styles of sewn bindings allow pages to open flat, while others cause the pages to drape.
Variations of notebooks that allow pages to be added, removed, and replaced are bound by rings, rods, or discs. In each of these systems, the pages are modified with perforations that facilitate the specific binding mechanism's ability to secure them. Ring-bound and rod-bound notebooks secure their contents by threading perforated pages around straight or curved prongs. In the open position, the pages can be removed and rearranged. In the closed position, the pages are kept in order. Disc-bound notebooks remove the open or closed operation by modifying the pages themselves. A page perforated for a disc-bound binding system contains a row of teeth along the side edge of the page that grip onto the outside raised perimeter of individual discs.