Chip Board, Kraft Paper and Cardboard is often used as part of the packaging for clothing.  Chipboard is often used in the folding process for shirts and other articles of clothing.

When discussing chipboard, grain direction is important because the direction of the grain provides strength or weakness in a particular direction.  Chipboard grain direction can be discussed in terms of short-grain or long-grain.  Paper (including chipboard) that is short-grain has its grain running in the shortest direction of the board, and that which is long-grain has its grain running in the long dimension.

Paper, like wood, has a grain.  And yes, chipboard is a type of paper product.

Several methods are available to determine Kraft paper grain.  Three primary methods (depending on the thickness) are folding, tearing or wetting. For heavy Kraft papers and cardboard, simply folding and creasing the material first in one direction parallel to an edge and then making a fold perpendicular to the first fold works well. The fold on the grain of the Kraft paper (which will be parallel to the direction of the fibers) will be easier to make and will have a sharper appearance. Tearing is another quick method that works on either thin or thick Kraft papers. Tearing a line down the length of the fibers produces a straighter separation and is somewhat easier to do than tearing across the fibers. The best method however is by taking a small square of the Kraft paper and quickly wetting one side only. As the water starts to expand the fibers on that side, the Kraft paper will begin to curl and hump up.