Whether you’re printing documents at home or the office, you know it’s wise to keep reams of paper on hand. But when you visit an office supply store, there isn’t a wealth of options. The standard paper size is 8.5 inches wide by 11 inches long.

Which invites a bit of pulpy pondering: Who decided that?

According to Marketplace writer Jack Stewart, the answer resides in the early days of paper production, when workers dipped paper molds made of wood into vats containing pulp and water. Once dried, you had paper.

This technique was pioneered by the Dutch paper makers of the 1660s. Through trial and error, the frames settled into a standard size of 44 inches long to accommodate the outstretched arms of the laborers. Divided up by four, that gave paper makers a paper size of 11 inches.

The width is a little bit murkier. It may be that the Dutch allowed for 17 inches on the mold to make room for watermarks. Cutting those in half meant paper that was 8.5 inches.

But that’s only part of the standardization process. With people using typewriters, copiers, and printers, it made little sense to have multiple sizes of paper available. There needed to be a one-size-fits-all philosophy. Paper coming in at 8.5 inches by 11 inches fit the bill—or, in this case, the typewriter. The size allows for a comfortable 65 to 78 characters per 6.5 inches per type, which is what you get after subtracting 1-inch margins.

This size became more ubiquitous when Presidents Herbert Hoover and Ronald Reagan both mandated the dimensions for all government forms in the 1920s and 1980s, respectively. (Hoover was looking to minimize paper waste.)

There is another standardized length of paper—14 inches. That extra 3 inches is thought to be the result of lawyers needing more room for wordy contracts, which is why it’s often referred to as legal-size paper. It’s gotten increasingly popular in restaurants, where the additional space is helpful to list menu items. Most paper, however, is the result of craftspeople who simply couldn't get their arms around anything else.

A version of this story originally ran in 2021; it has been updated for 2023.

This article was originally published on www.mentalfloss.com as The Reason Why a Standard Piece of Paper Is 8.5 Inches by 11 Inches.