2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/229454A convex surface that is flat everywhere but on finitely many smooth curves (or "seams") and points is a seam form. We show that the only creases through the flat components of a seam form are either between vertices or tangent to the seams. As corollaries we resolve open problems about certain special seam forms: the flat components of a D-form have no creases at all, and the flat component of a pita-form has at most one crease, between the seam's endpoints.revisedComputational Geometrytext