Detail from a copy of a 1975 memorandum duplicated using the spirit process. (Courtesy of J. Murrey Atkins Library, University of North Carolina at Charlotte, MS0044)n. (also spirit duplicating)a method of copying documents using a master sheet created with aniline dye ink, which, when placed on a rotary drum press and moistened with a methyl alcohol solution, transfers the ink to blank sheetsClark 1964, 392Proliferation or printing is a costly operation and a menace to practical records management. Moreover, the problem is further complicated by the advent of office copying machines and the large number of spirit duplicating machines, the use of which is uncontrolled.Proudfoot 1972, 36Spirit duplicating today is sometimes referred to somewhat erroneously as hectograph after its ancestor the gelatin process.Teper 2007, 18In spirit duplication, a negative master is first produced by writing or typing on a sheet of non-absorbent paper backed with a carbon containing dye suspended in a binder. In 1937 Ditto Inc. marketed the carbon sets that had the master sheet in front, backed with a sheet coated with thick, paste-like ink. This waxy ink is both carbon pigment based with a dye component that can be solubilized in alcohols and other volatile solvents. This dye was typically purple in color, indicating that it was likely aniline dye. When pressure is exerted onto the master sheet, the copy ink transfers from the backing sheet to the back of the master in negative. The master is then mounted to the cylinder of the machine and wetted with a solvent (frequently methanol or other alcohols) to partially solvate the ink. The ink then transfers to any copy paper by being pressed together through pressure rollers.Batterham 2008, 51Spirit duplication masters could be produced in a number of ways. The most common method involved a specially prepared composite comprising a sheet of smooth paper and an attached paper or plastic sheet coated on one side with a waxy ink. Typing or writing on the attached sheet caused transference of the ink to the paper. When finished, the attached sheet was discarded.Batterham 2008, 55Spirit duplication inks were based on a wax and formulated to be readily soluble in a volatile hydrocarbon spirit. To allow for the production of a good number of copies from a master, the process used aniline dyes due to their high tinctorial power. The inks were often strongly coloured, the most common colourant being crystal violet as used in hectography. Blues and blacks were also common.Dana 2021, 9It wasn’t until the invention of hectography, spirit duplication, and mimeography and the ability to easily make dozens of copies that “duplicating” technology quickly became popular in classrooms, churches and meeting halls. More and more non-printers gained the ability to print low-cost multiples, and simultaneously, cheap copies also became a distribution platform for the ideas of under-represented communities, bohemian artists, and political dissidents.
Notes
The spirit duplicator was first introduced in the early 1920s and continued to be widely used as a low-cost alternative to photocopiers in schools, churches, unions, and other small organizations until the 1980s. The alcohol solution used during its heyday caused the documents to carry a distinctive odor, although less fumy alternatives continued to be available for hobbyists and creators who used this method for producing media such as zines into the twenty-first century. Duplicates produced using this process are often referred to as dittos and the equipment that created them known as ditto machines due to the success of the Ditto Corporation in this market. One of the hallmarks of documents created using this method is the distinctive purplish hue that was typical (although not universal) of the aniline dye inks used. The ink is unstable in ultraviolet light and soluble in water.
Detail from a copy of a 1975 memorandum duplicated using the spirit process. (Courtesy of J. Murrey Atkins Library, University of North Carolina at Charlotte, MS0044)
n. (also spirit duplicating)
a method of copying documents using a master sheet created with aniline dye ink, which, when placed on a rotary drum press and moistened with a methyl alcohol solution, transfers the ink to blank sheets