This is a not a photocopy, but a reproduction of an original Thread Forms and Formulas Chart by Atlas Press Co.  Chart measures 16" x 21".  This poster has been professionally digitally edited, retaining some of the slight imperfections of the original publication from the 1940's.  Professionally printed on 36 lb high resolution coated bond matte poster paper, comparable to the original print.  Suitable for framing.  Excellent addition to your shop. 

This is one of a set of four Atlas Press posters currently available in my store.