Four small, wooden blocks hang from a yellow string around my neck. Though they resemble antique children’s toys or minimalist Etsy crafts, they were stolen from a mostly defunct letterpress shop. I didn’t know it at the time, but these wood blocks are probably centuries old—they were once used to create spaces between words on a letterpress printer.

In the years after college, I learned how to make a book traveling from print shop to print shop across the country. I made paper by hand from recycled cotton tee shirts. I bound pages together and stitched intricate leather shells for them. I silk-screened, marbled, and block-printed paper. I sorted metal and wood type into words, composed pages, and ran them through countless presses.

When people think of printmaking, most imagine the printing press itself—someone running paper through a large machine, turning out sheets of words or colorful posters. But in truth, the actual printing portion takes less than half the time. To understand letterpress printing, imagine that every letter you see on your screen is an object, a tiny piece of metal. Not only is every letter an object, but every space between every letter is also an object. Every space between words, every space between lines—every bit of white space is an object. When typesetting, a printer has to think about negative space as something tangible.

This is where the en space comes in. An en space is a rectangular piece of metal or wood whose primary purpose is to be smaller than the metal or wood type being printed. The en space isn’t type-high—it doesn’t sit proud like an ordinary character—so it doesn’t catch ink when it’s run through the press. It just holds printable type together in a tight grid, creating spaces between words. It is never seen, but without it, everything printed would be nonsense.

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Today, people associate reading with solitude and quiet, but this wasn’t always the case. In the Middle Ages, the Bible was only reproduced in its original Latin scriptura continua, meaning there were no spaces between the words. To differentiate between words, readers had to sound them out; no one read silently.

We have the Irish to thank for the spaces between words. When Roman Catholicism made its way to Ireland by the fifth century, the Irish were given Bibles written by hand in the original scriptura continua Latin. Having never heard Latin spoken before, the Irish had an understandably difficult time reading it. The solution? When copying the Bible, they separated the words with a small space.

The invention of spaces between words changed the process of reading entirely. In his book Space Between Words, the medievalist Paul Saegner argues that spaces were directly responsible for the development of silent reading. “Altering the neurophysiological process of reading simplified the act of reading,” he explains. Specifically, it allowed readers to comprehend the text separate from its oral performance. By adding space and reading silently, early readers could take in information more quickly.

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In 1455, Gutenberg printed the first Bible with moveable type. During the centuries since the Irish developed spaces between words, the process of copying texts by hand has transformed into an art form in and of itself. When the 15th-century Italian scribe Poggio developed what is now the template for Roman typefaces, he did so in the service of constructing a clear and legible script that more people could read, thus making different texts more available to a wider audience.

To most, the introduction of the printing press, with its identical typefaces, indicates a rise of uniformity, a removal of the beautiful scripts of Poggio and other scribes. On the contrary though, no two printed Gutenberg Bibles are the same. As Matthew Battles points out in Palimpsest: A History of the Written Word, the Gutenberg Bibles (and many of the Bibles printed later) were typeset with ample blank spaces. “Well into the 16th century,” Battles writes, “printed books were produced with space in the margins for custom-painted borders and added illustrations. Far from putting the scribes and illuminators of the late Middle Ages out of work, the technology of the press offered these artisans a new medium and new markets for their labor.” The empty space afforded by wood and metal blocks allowed printed texts to be individualized.

Although computers can mimic the style of letterpress printing, there is still demand for the original process—people like to see the embossment from the wood and metal type, the visual quirks of the old printing blocks, and the small discrepancies between each pull of the press. They are small things, but still things that computers can’t do.

After mapping out a design for each poster or invitation, a typesetter uses a composing stick, a small adjustable tray that holds type, to organize lines of text into a standard grid. When putting together type, I would first retrieve each letter I needed for the line of text I was working on. After I had assembled all of the letters in my composing stick, I would add spaces—the pieces of wood and metal small enough that they don’t print. The trick was equally distributing space between the words and then adding spaces between the letters until the line of type filled the length of the composing stick. As the designer Ellen Lupton writes in her book Thinking with Type, “Design is as much an act of spacing as an act of marking.”

Typesetting is slow. As I arranged and organized letterforms, I would pass the time talking with the two printers who ran the shop—about art, about politics, about creative anxiety, about the individual merits of the different sandwiches at the deli down the street. I also spent a good deal of time taking apart the designs that had already been printed—going letter by letter and space by space, putting each bit of metal and wood type back into its correct drawer or cubby so it could be used again for another design. Inefficiency is a virtue in a print shop. When no one is running the press, everything can be cleaned up and reconfigured. The spaces aren’t just in the composition, but in the workplace as well.

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In letterpress printing, spaces are added and removed as necessary to make sure that the words are justified to the margins of the page. But with the introduction of the typewriter, spaces became uniform. Christopher Latham Sholes invented the first successful typewriter in 1867. It resembled the typewriter we know today, except that it printed on the underside of the roller; the typist could not see the result until after finishing. Because typewriters work in a continuous line, there isn’t any way to adjust how much space goes between letters and words. If you look at the original typewritten manuscripts of any modern writer, you’ll see that the right hand margins are uneven, creating jagged blank spaces. The margins are always corrected in the final printing of the book, which by the 20th century was primarily done through offset printing, a process that transfers an entire page or image at a time from a single plate, as opposed to the individual forms of letterpress printing.

Today’s word processors mimic letterpress printing more closely than they do typewriters. Although the computer keyboard isn’t all that different from an early typewriter’s, the word processor can space and arrange text on a page after it has been typed. Many of the fonts in an ordinary word processor can also be found in the drawers of a print shop.

The language of computational typesetting is all adopted from letterpress, too. When graphic designers talk about kerning—the technical term the amount of space between letter and words—they’re building on the printers’ tradition of carving away space on individual letter blocks—“A” and “V,” for example—so they would fit together tightly on the press. Any student who has tried to make a paper appear longer by adding space between lines is using leading, a letterpress term that refers to the process of adding strips of lead horizontally between lines of type. What we know as the standard 12-point font was originally called a pika, the standard measurement for any given typeface in a printer’s drawer. The terms uppercase and lowercase come from the fact that those typefaces were literally separated in an upper and a lower case.

Letterpress has left its marks all over contemporary design. The grid is a cornerstone of graphic design, fundamental to any program in the Adobe Suite. While designing with a grid dates back to the ancient Egyptians, letterpress transformed how designers think about type within that grid. For letterpress printers, the grid works on both an aesthetic and functional level. When a line of type doesn’t fill the entire space on the grid, typesetters will add flourishes and dingbats to compensate for the extra space. In addition to looking better, the embellishments also help the letters print more evenly on the press—too much empty space and the rollers of the press will place extra weight on individual blocks, damaging the blocks and the print itself.

As letterpress printing began to be used for commercial fiction, newspapers, and playbills, typesetters started mixing different typefaces together, switching between roman and italic to add emphasis to different words. Of course, there is a practical explanation for this as well: A letterpress shop only has so many copies of the same letter. If, for instance, a typesetter is compiling a line of text in 24-point Franklin Gothic and needs eight uppercase ‘A’s but only has five—perhaps one word can be set in an altogether different typeface. In 19th-century design in particular, there’s a distinct style of alternating very small fine print with large bold headlines, leaving virtually no white space between. As advertising became more essential to printing, blank space meant lost profits.

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Since then, blank space has become a unique commodity in print. Minimalist design responds to the scarcity of emptiness, making a point of using as little material to say as much as possible. In the wake of national tragedy or political strife, it is not uncommon for entire pages of The New York Times to be bought out and feature only a few words, a short letter, or a list of names. The negative space indicates that this concise message is more dear, in both its meaning and its cost, than whatever would otherwise occupy the page.

Long before minimalism exalted the aesthetic and commercial value of blank space, the ordinary folk who operated printers held it in their hands, in the form of en spaces, leading strips, and the wedges of metal that hung off kerned glyphs. It didn’t take a turtleneck to see why blank space can be moving.

This article appears courtesy of Object Lessons.