A half-fold is a sheet of paper folded in half. It’s also sometimes called a 4-pager or 4-page brochure.

half fold

A half fold is a simple, common brochure format that works well for paper that is 8.5 x 11” (folds to 5.5 x 8.5) and 11 x 17” (folds to 8.5 x 11).

A half-fold can also be applied to any other paper size, but these two just mentioned are used frequently for brochures and marketing materials.