Any saw blade can be turned into a DIY saw, as either a bucksaw or bow saw.
DIY bucksaws are easy to assemble and just as easily disassembled for packing.
Photo courtesy Paladin Press
"Makeshift Workshop Skills for Survival and Self-Reliance", by James Ballou, teaches the skills necessary to build and repair anything with nothing but salvaged material, your hands, and a bit of imagination.
Cover courtesy Paladin Press
While bucksaws can be made in various sizes, the DIY bow saw may be easier to assemble in the field.