A mimeograph is a duplicating machine used to make copies by pressing ink through the holes of a stencil and onto sheets of paper. This type of machine is also known as a stencil duplicator, mimeo, or mimeograph machine. There are various kinds of mimeographs, including single drum and dual drum versions, and they can be powered by an electrical motor or hand cranked to produce copies without the use of electricity. The mimeograph was invented by Thomas Edison in the late 19th century, and mimeographs were widely used in offices, schools, and similar settings until the late 1960s when they began to be replaced by other duplicating machines, such as photocopiers and the offset printing press. Mimeographs are uncommon today, but are still favored by some users because they are cheap, reliable and simple to operate.
The stencil used to make copies in a mimeograph is a flexible sheet made from coated material, commonly some type of waxed paper. To create a document to be copied, the stencil material can be put into a mechanical typewriter without ink. Typing each letter then punches holes in the material, creating a stencil. A stylus or other sharp implement can also be used to create images and other types of designs on the stencil material.
The earliest mimeograph invented by Edison was a flatbed version, but this was soon replaced by mimeographs using rotating drums or cylinders. In a single drum mimeograph, the finished stencil is wrapped around and fastened to a cylinder that has been saturated with ink. Copies are made as the cylinder spins, pressing the ink through the holes in the stencil and onto sheets of paper that pass through the mimeograph. In a dual drum machine, the stencil is attached to a silkscreen belt that covers two cylinders. Rollers apply ink to the cylinders as they spin, and the ink is pressed through both the silk screen and the stencil onto sheets of paper to create copies.
In a single drum mimeograph, multi-color images can be created by switching out the cylinder for one saturated with different colored ink. Today, photocopiers, laser and inkjet printers, and other types of printing devices and duplicating processes have largely replaced the use of mimeographs. However, mimeographs are still used in some developing countries because they are a cost-effective and easy way to make copies, and also because hand-cranked mimeographs can be used even in areas where there is no access to electricity.
How the Mimeograph Machine Made Teachers’ Lives Easier
Before duplication machines, teachers had to handwrite or type multiple worksheets for their students. Fortunately, the mimeograph machine made it easier to provide students with information.
- The Machine Made Exact Copies – As teachers spent hours making multiple copies of papers by hand, it was inevitable that mistakes could happen. Using the mimeograph machine allowed educators to create exact replicas of their material, ensuring all students receive the same information.
- Teacher’s Saved Time – Writing or typing duplicates of anything takes a lot of time. By using the mimeograph machine, teachers spent more time with their students and less time preparing for the next lesson.
- The Machine Was Affordable – Since schools operate within a limited budget, they often don’t have money for costly office equipment. The mimeograph machine was affordable for nearly all schools, and teachers could even crank it by hand.
School Newspapers Became Popular
As the mimeograph made teaching easier, schools also used them to print newspapers. Students in higher education had a chance to share their creativity by designing and writing the paper. The mimeograph machine’s easy use and low cost opened many doors in the education industry.
The Uniqueness of Mimeograph Paper
The original paper used to make a stencil for the mimeograph machine came from mulberries. This thin paper had a wax coating to prevent the form from absorbing ink. Eventually, a paper with longer fibers became popular because it was more durable than the mulberry. Manufacturers coated this newer material with cellulose instead of wax.
The thin stencil paper was difficult to get through typewriters without crinkling, so it was attached to a sturdier piece of cardstock. Manufacturers bound the pages at the top, and then people separated them before using the stencil in the mimeograph.
There were three common ways to create stencils for the mimeograph machine.
- People most commonly used a typewriter to create stencils. A setting on the machine stopped the ink ribbon from raising when a user pressed the keys. This action allowed the sharp points of the metal-type elements to break through the coating and create space for the ink to flow through the thin paper.
- People could also use stencil paper to create illustrations. Pictures could be made by hand using a stylus. If someone made a mistake, a special correcting fluid could recoat the paper to prevent ink penetration in that spot. Once it dried, people could draw new images over that area.
- Some people used an electrostencil machine to make stencils. This process worked by using an electric spark to burn through the ink on the stencil. The drawback to this was that it created dangerous ozone gasses and was very time-consuming. These stencils were also not as sharp as typewritten creations but were easier for making illustrations.
A few manufacturers still make mimeography machines. Though they are different from the machines made in the early and mid-1900s, there are some similarities.
How They Work
Modern mimeographs are sometimes called copyprinters or digital duplicators. These work by scanning a document through the machine, and a thermal head creates the stencil. The stencil roll is inside the machine and is made from long-fiber non-woven material covered in a thin polymer coating. The stencil then rolls through ink as the traditional mimeographs did.
The ink used in these new machines is made from soybean oil and comes in various colors. This unique ink requires uncoated paper for proper printing. An advantage to this ink is that it is not heat set, so the documents can be used in a laser printer without damaging the soyink image. A different stencil for each color is required to make an image with multiple tones. After the machine prints the first layer of colored ink on all documents, the pages are reloaded with a different stencil and another color for a second pass.
Why People Choose a Mimeograph
Despite the availability of modern copy machines, scanners and digital documents, mimeographs still have some advantages over these machines. Newer mimeographs are more economical than photocopiers, making them a better option for lower-income areas. Some still offer the ability to make copies without electricity. Another advantage is that these machines can print hundreds of documents a minute, making them faster than some of the top printers and copiers available.
Companies can buy or rent these machines to be shipped worldwide. Some are also available to try in different locations throughout the United States.