Sidetaitos

Sidetaitos is a Finnish term used to describe a fold made along the side edge of a sheet, card, or page. It appears in Finnish-language texts on papercraft, bookbinding, and graphic design to refer to a crease oriented parallel to the side margin. The concept is practical for forming side flaps, preparing the edge for binding, or creating a guided edge for subsequent folding.

In papercraft and origami practice, sidetaitos denotes a side crease produced by aligning a fold line with a reference edge and applying pressure to create a sharp crease. In bookbinding and printing, sidetaitos can describe techniques that produce a reinforced or structured side edge, such as methods used to assemble covers, endpapers, or pamphlets with a consistent margin.

Terminology can vary by workshop or publisher; some sources employ more specific terms for particular fold configurations. Overall, sidetaitos refers to the family of folds oriented toward the side of a sheet, rather than those placed at the center, top, or bottom. It forms part of the basic vocabulary of taitos (folds) used in design, craft, and manufacturing workflows.