Sidefold

Sidefold is a folding operation in which a portion of a sheet is folded toward the side along a crease that runs roughly parallel to the edge of the sheet. This creates a side panel or flap that can be used to reduce width, form a pocket, or secure a closure in a craft or packaging context.

In origami and paper crafts, a sidefold refers to folding a portion of the work along a line parallel to one edge, typically creating a narrow strip or flap that lies beside the main body. Sidefolds may be implemented as valley folds or mountain folds, depending on whether the crease creates a recessed or projecting surface. Sidefolds are common in foundational folds and in models that require additional layers along the sides.

In packaging and printing, sidefolds are used to produce side panels on brochures, pamphlets, and envelopes. A sidefold can create a flap for sealing or a gusset for expanding capacity. When used in binding, a sidefold helps form a spine or gutter that aligns with the sheet edges.

Technique notes: precise alignment with the edge or corner helps ensure uniform width after folding. In origami instructions, sidefold steps are usually labeled and accompanied by diagrams showing the crease direction and resulting shape.

See also: folding, origami, paper craft, bookbinding, envelope design.