Original drawings on paper vellum

The base drawing that was created was typically on tracing paper, paper vellum, or some other type of thin layer cloth that would allow light to pass through the chosen medium. These base drawings would then be turned into blueprints. More can be seen on how blueprints were made from these drawings by going here: Blueprint
*I have found, since creating this site initially, that there is another item that may have been used for the original drawings. Information about this material can be found by following the link here: Drafting linen