Paper grain direction plays a big role in every printing and binding job. Using the proper grain will ensure a quality job, not only in looks but in durability.
What is Grain?
A paper’s grain is the direction in which the majority of the fibers lie. The grain is determined during the manufacturing process and is referred to a couple of different ways. Grain short papers are those papers on which the grain runs parallel to the short edge of the sheet. Grain long refers to papers where the grain runs parallel to the longest edge.
How do I know which direction the grain runs?
Paper mills specify grain a couple of different ways. In addition to calling papers grain long or grain short, they may underscore the dimension number which runs parallel to the grain. For example, 12″ x 18″ specifies that the grain runs along the 18″ edge, or is grain long. Many mills list the grain direction last when listing dimensions but this may fluctuate from mill to mill.
If the paper isn’t marked and you need to determine grain, try folding a piece of paper twice, once with the fold parallel to the long edge and once with the fold parallel to the short edge. One fold will be a cleaner edge than the other. The cleaner edge is folded with the grain.
What grain should I use?
As a general rule of thumb, if bindery processes such as folding, perfect binding, or mechanical binding are part of the finishing work, always try to have the grain parallel to the folding or binding edge. Not only will you have a better looking final piece, but in the case of books, the finished product will be more durable. Never mix grain directions within a book as the different grain papers will actually work against each other.
If no finishing other than cutting is needed, most pieces benefit from printing on long grain stock. Long-grain stocks will give business cards, postcards, posters, letterhead and other similar items stability and make them resistant to drooping or buckling.
Economics also play a role in grain determination. The most efficient cut may not leave the sheet in the proper orientation for printing and/or binding. In this case, it is up to you to find a balance between design, printability, and price.