crease (writing guide); creasing; crease line
Refers to a pre-made crease or fold line on paper, often used as a guide for writing or folding. Common in stationery and paper-craft contexts.
This writing paper has a crease line, so you can fold it straight.
Please fold the letter in thirds along the crease lines.
Variant with okurigana; both spellings are used.
Compound of 折り (ori, 'folding') and 罫 (kei, 'ruled line'). The kanji 罫 is associated with lines or rules, and the combination describes a line made by folding or a crease used as a guide.