COPYING OF ENGINEERING DRAWINGS AND DOCUMENTS.

One of the many aspects of modern industrial and commercial life which tends to be taken for granted is the availability of copies of drawings and documents at a reasonable cost. Prints of drawing, carbon copies and photocopies would seem to be vital to industrial growth, but, while the first commercial copying process appeared two hundred years ago, it is only in the past century that copying by non-manual methods has been widely adopted. This paper will trace the development of copying processes and try to explain why they were not adopted as rapidly as we might expect. Descriptions of the various types of copies may assist in identifying archival material and show how many apparently similar copies could be produced by different processes.