A vertical stand-up pouch or flexible package, and method for manufacturing same, constructed by modification to existing vertical form and fill packaging machines. The invention involves producing a vertical stand-up pouch from a single sheet of packaging film by creating a vertical crease along one edge of a packaging film tube prior to forming a transverse seal on the tube. Said vertical crease is formed using a stationary tucker bar positioned outside the packaging film tube and between two forming plates positioned inside the packaging film tube.
