When I was at the library recently, I reviewed a 1946 publication by an urban planning agency. The purple color of the text of the document jogged my memory. The pages had been printed on a ditto machine. I had not seen the output from one of those types of printers since the day when I wore a younger man’s clothes.

According to my trusty 1965 World Book encyclopedia, the ditto machine (spirit duplicator) and mimeograph (stencil duplicator) were competing technologies in the document-copying market. I learn that the mimeograph can be traced to inventor Thomas Edison, who patented a stencil duplicator called “autographic printing.” Albert Blake Dick invented the mimeograph in 1884, and Wilhelm Ritzerfeld gave us the ditto machine in 1923.

The mimeograph printing process used an ink-filled cylinder and ink pad. Documents had to be prepared on a special wax-covered stencil on a typewriter which had its ribbon disengaged. The typewriter thus made impressions in the stencil, which were filled with ink and squeezed onto paper by the mimeograph’s roller. The stencils could also be used with drawings made by hand.

In contrast, the ditto machine used no ink. The user typed, wrote, or drew on a ditto master sheet which was backed by a second sheet of paper coated with a dye-impregnated, waxy substance. The inscribed image appeared on the back of the ditto sheet in reverse. The ditto machine used an alcohol-based fluid to dissolve some of the dye in the document, and transferred the image to the copy paper.

Though other colors of ditto sheets were available, purple was commonly used. In elementary school, I remember that the teacher would distribute drawing sheets for us to color. The sheets had been through the ditto machine, which gave purple outlines to the drawings of fruit, animals (mostly lions and tigers and bears), letters, numbers, and everything else that we were asked to stay within the lines while we colored.

The output of the ditto machine had a special aroma. Students could tell when a class assignment was hot out of the machine by the strength of the odor of the pages. The smell came from the ditto machine’s duplicating fluid, a mix of methanol and isopropanol.

The school office staff typed announcements, and then ran them through the ditto, for students to take home. “Now, boys and girls don’t forget to give this to your parents so that they will know about our field trip” was something that the teacher often said while handing out the purple forms. The night before a school play, some moms found crumpled purple announcements in which they were asked to make costumes.

I was on the newspaper staff in junior high, and our school periodical was printed on a mimeograph. I recall typing my feature articles on one of the stencils, though I didn’t get to run them through the machine (sigh). The newspaper articles had to be left and right-aligned, which required that I insert enough extra spaces between words to create an even right margin. To do that, I had to type a draft of each article, pad each line with slashes (/), and then re-type it while I counted the number of slashes and inserted extra spaces to match. Today’s word processing software and printers make all of my effort back then seem primitive.

By high school, my newspaper articles were printed on fairly sophisticated printing machines in the school’s print shop. I believe that teachers still used ditto sheets for homework. I can still see those multiple choice tests in garish purple color.

In college, the modern age of the Xerox copying machine had arrived. Even after competitors had joined the copying machine market, “Xerox” was used as the name for copies made on any brand of copying machine. Reminds me of my grandmother, who always said that she had some Jello and fruit salad in the “Frigidaire,” even though her cooler was a General Electric.

Electronic, computerized copying machines have all but eliminated the humble mimeograph and ditto machine. The A.B. Dick Company filed for Chapter 11 bankruptcy protection in 2004. The company is now owned by Presstek. I searched the new owner’s Web site, and found that mimeograph and ditto owners can still buy supplie through Presstek.

The mimeograph and ditto machines helped to print the pages which are now history, and have now themselves become a part of history. If you have mimeograph and ditto memories, please send me an e-mail at jolleyh@bellsouth.net.