noun
long grain (paper)
Refers to paper where the grain direction runs parallel to the longer side. Often abbreviated as Ｔ目 in technical contexts.
この紙は縦目なので、折り目がつきやすい。
This paper is long grain, so it creases easily.
印刷するときは、紙の縦目を確認してください。
When printing, please check the paper's grain direction.
横目 refers to short grain paper, where the grain runs parallel to the shorter side.
Compound of 縦 (tate, 'vertical') and 目 (me, 'grain' or 'texture'), referring to the direction of paper fibers.