The story of print & paper

Photocopying, offset lithography and digital printing

Copy Express may not actually exist without a very clever chap called Chester Carlson, a patent attorney in New York. The process of copying large amounts of documents had become very tedious for poor Chester, so he conducted photoconductivity experiments in his kitchen. In 1938 he applied for a patent for the process known as electrophotography and made the first "photocopy" using a zinc plate covered with sulphur. His patent was accepted in the 1940’s and so for the next few years he worked his socks off, unsuccessfully, to sell his invention to some very large and some very well known corporations, but at the time people just didn’t see the need for an electronic machine to replace carbon paper or duplicating machines, and especially so for a process that was still largely underdeveloped. Chester needed a lucky break.

In 1944 some luck arrived, the Battelle Memorial Institute, a non-profit organisation in Columbus, Ohio, contracted with Carlson to refine his new process and over the next five years the institute conducted experiments to improve the process of electrophotography. In 1947, Haloid Corporation approached Battelle to obtain a license to develop and market a copying machine based on this technology. Haloid felt that the word "electrophotography" was too complicated and didn’t have good recall value so after consulting a professor of classical language at Ohio State University, Haloid and Carlson changed the name of the process to "Xerography," which was derived from Greek words that meant "dry writing." Haloid called the new copier machines "Xerox Machines" and, in 1948, the word Xerox was trademarked.

Colour toner became available in the 1950s, although full-colour photocopiers were not commercially available until 1968, which used a dye sublimation process rather than conventional electrostatic technology. The first electrostatic colour copier came out in 1973. In the past colour photocopying has raised concerns about counterfeiting; most countries have introduced anti-counterfeiting technologies into their currency specifically to make it harder to use a photocopier for counterfeiting. Most photocopying machines, including ours at Copy Express, contain special software that prevents copying or scanning of currency and some I.D. In recent years, all new photocopiers have adopted digital technology thus replacing the older analog technology. With digital copying, the copier effectively consists of an integrated scanner and laser printer. This design has several advantages, such as automatic image quality enhancement and the ability to "build jobs" (that is, to scan page images independently of the process of printing them).

Photocopiers haven’t really changed too much over the years, new types of finishing units and thicker paper can now be used, the machines have become quicker and smaller, plus are more eco friendly and easier to use. Much the same can be said about printing too, offset lithography is not toner based like photocopying but is a process of ink on paper using a printing press. It is the workhorse of printing and almost all commercial printers offer it, but the quality of the final product is often due to the guidance, expertise and equipment - Copy Express has over 15 years experience in this field and pride ourselves on our top quality printing. Offset works on a very simple principle: ink and water don't mix. Images (words and art) are put on plates which are dampened first by water, then ink. The ink adheres to the image area, the water to the non-image area. Then the image is transferred to a rubber blanket and from the rubber blanket to paper. That's why the process is called "offset" -- the image does not go directly to the paper from the plates. Offset printing is still the most common form of high-volume commercial printing, due to advantages in quality and efficiency in high-volume jobs. While modern digital presses are getting closer to the cost / benefit of offset for high-quality work, they have not yet been able to compete with the sheer volume of product that an offset press can produce. Many modern offset presses are using computer to plate systems as opposed to the older computer to film workflows, which further increases their quality.

Many of our clients still prefer to use offset litho, but digital printing is becoming more popular, some benefits to digital are smaller runs can be quicker to produce, every impression made onto the paper can be different (similar to photocopying), The ink or toner doesn’t absorb into the paper, as does conventional ink, but forms a layer on the surface, and a final selling point for some is that it generally requires less waste in terms of chemicals used and paper wasted, therefore having less impact on the environment.

Of course, photocopying and printing would both not be here without paper, and more importantly a standard for paper and paper sizes. One of the oldest written records regarding the aspect ratio for paper sizes is a letter that the physics professor Georg Christoph Lichtenberg (University of Göttingen, Germany, 1742 - 1799) wrote to Johann Beckmann. In it, Lichtenberg explains the practical and aesthetic advantages of the aspect ratio, and of his discovery that paper with that aspect ratio was commonly available at the time. After introducing the meter measurement, the French government published the “Loi sur le timbre” (no. 2136), a law on the taxation of paper that defined several formats that already correspond exactly to the modern ISO paper sizes: “Grand registre” = ISO A2, “grand papier” = ISO B3, “moyen papier” = ISO A3, “petit papier” = ISO B4, “demi feuille” = ISO B5.

The French format series never became widely known and was quickly forgotten again. The A, B, and C series paper formats, which are based on the exact same design principles, were completely independently reinvented over a hundred years after the “Loi sur le timbre” in Germany by Dr. Walter Porstmann. They were adopted as the German standard DIN 476 in 1922 as a replacement for the vast variety of other paper formats that had been used before, in order to make paper stocking and document reproduction cheaper and more efficient. Porstmann’s DIN paper-format concept was convincing, and soon introduced as a national standard in many other countries: 1920 - 1940: Belgium, Netherlands, Norway, Switzerland, Sweden, Soviet Union, Hungary and Italy. 1941 - 1960: Uruguay, Argentina, Brazil, Spain, Austria, Romania, Japan, Denmark, Czechoslovakia, Israel, Portugal, Yugoslavia, India, Poland and United Kingdom. 1961 - 1980: Venezuela, New Zealand, Iceland, Mexico, South Africa, France, Peru, Turkey, Chile, Greece, Zimbabwe, Singapore, Bangladesh, Thailand, Barbados, Australia, Ecuador, Columbia and Kuwait.

North America never signed up to the standard and the historic origins the U.S. Letter format, and in particular its rationale, seem rather obscure, the earliest documented attempts to standardise U.S. paper format used a completely different format - in 1921, the U.S. Secretary of Commerce declared a 203mm × 267mm format to be the standard for his department, but it wasn’t until 1980 that the U.S. Letter format (216 × 279 mm) became the new official paper format for U.S. government offices.

It finally became both an international standard (ISO 216) as well as the official United Nations document format in 1975 and it is today used in almost all countries, leaving North America as the only remaining exception. ISO paper sizes are based on the metric system and ISO 216 defines the A series of paper sizes based on these simple principles: A0 has an area of one square meter. The height divided by the width of all formats is the square root of two (1.4142), plus the area of the page is rounded up or down to the nearest metric value in mm (millimetres) - e.g. the height of A1 = 841mm, but the width of A2 = 420mm. A0: 841mm x 1188mm, A1: 594mm x 841mm, A2: 420mm x 594mm, A3: 297mm x 420mm, A4: 210mm x 297mm, A5: 148mm x 210mm, A6: 105mm x 148mm. Put simply: A1 is an A0 cut into two equal pieces.

For applications where the ISO A series does not provide an adequate format, the B series has been introduced to cover a wider range of paper sizes, and the C series of formats has been defined for envelopes. The formulas between ISO series’ get slightly more complicated, but put very simply, an A4 size sheet fits into a C4 envelope.

The ISO standard paper size system covers a wide range of formats, but not all of them are widely used in practice. Among all formats, A4 is clearly the most important one for daily office use, other main applications of the most popular formats are as follows: Technical drawings & Posters A0 & A1, Flip charts A1 & A2, Drawings, Diagrams & Large tables A2 & A3, Letters, Magazines, Forms & Catalogues A4, Notepads A5, Postcards A6, Books B5, A5, B6 & A6, Envelopes for A4 letters unfolded C4, folded once C5, Newspapers B4 & A3, Playing cards B8 & A8.