Grain

Grain is the term used to describe the inclination in a sheet of paper to curl, fold, or tear in one particular direction. Knowing the grain of a sheet of paper is particularly important whenever the paper is to be used as other than a flat surface: whether it be in books, paper crafts, or three-dimensional work.

Grain originates in the way the paper is formed. Paper is made up of many small fibers which are considerably longer than they are wide. Because of movements used in forming a handmade sheet in the traditional Western manner--dipping into and pulling out of a vat--the fibers are naturally oriented in a direction parallel to this motion. The "papermaker's shake" which is done right after the mould is lifted from the vat is intended to aid the distribution of pulp evenly across the surface of the mould. It also, however, helps compensate for the common alignment of fibers and provides strength to the sheet. Nonetheless, there is still a marked grain in most handmade sheets made in this manner.

Most Japanese-style nagashizuki papers would have as much or even a greater grain direction, as the formation technique, which may include several dips of the mould into the vat, is very markedly unidirectional. Paper formed from pulp poured onto a mould, such as paper made using the Nepalese technique, is much less likely to have a distinct grain, because of the relatively random way in which the pulp makes contact with the screen.

There are several ways to check for grain in a piece of paper. If you bend the paper over, without creating a fold, it will be stiffer perpendicular to the grain direction than with the grain. A full fold will also be harder and less even if done against the grain than with it. Tearing the paper should also be noticeably easier with the grain than against it. Another way to test, is to spray the paper on one side with water, and it will curl with the grain.

Grain is important to be aware of when working with paper because of the relative strength of the forces which hold the fibers together. In uncontrolled environments, especially with fluctutations in humidity, fibers will absorb moisture and swell in accordance with the grain. Folds will be cleaner and bound papers will work better if sewn or attached in a grain direction.