Margaret E. Knight (-) was an American inventor best known for a machine that mechanized the manufacturing of flat-bottom paper bags, which had previously been produced by hand. Flat-bottomed paper bags transformed retail commerce and became indispensable to workers and students carrying a 'brown bag' lunch, yet its ubiquity makes it easy to forget'along with the name of the person responsible for its production.

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As a child, Knight was more interested in tools than dolls and frequently made or improved toys for her brothers and other children. She also began working with machinery at a young age. Born in Maine, her family relocated to Manchester, New Hampshire after the death of her father so that her mother and two brothers could work in the cotton mills. Knight claimed that her first invention came soon after she began working in the mills at age 12. After witnessing a steel-tipped shuttle fly out of a loom and seriously injure a worker, a common hazard in the mills, she devised a shuttle-restraining device. The device was placed on all the looms in her mill and before long other mills in the area adopted its use.

Example of a steel-tipped shuttle from the 19th century. Courtesy Cooper Hewitt Smithsonian Design Museum, Gift of Mrs. DeWitt Clinton Cohen.

Knight left the mills in her late teens due to poor health. As an adult she gained valuable experience working in upholstery, photography, engraving workshops, and home repair. She developed skills and gained a deeper understanding of processes with each new experience. Around , Knight began working for the Columbia Paper Bag Company in Springfield, Massachusetts and soon began developing a machine that could cut, fold, and paste flat-bottom paper bags, eliminating the time-consuming labor otherwise required to make them by hand.

Page from Margaret E. Knight's patent application for a paper bag machine with patent number and award date stamp. National Archives and Records Administration, Records of the Patent and Trademark Office, NAID .

Knight worked on her machine for over two years, eventually perfecting a prototype in wood before hiring a machinist to fabricate the working model needed to apply for a patent. While under construction, another machinist, Charles Annan, stole Knight's design and submitted it as his own to the U.S. Patent Office in Washington D.C. Upon learning of the fraudulent claim, Knight initiated a patent interference suit against Annan and hired a lawyer to defend her work. Knight produced substantial evidence to support her claim including drawings, notes, entries from her personal diary, and testimony from her landlady, former employer, and machinist. Knight refuted Annan's weak argument that as a woman she was incapable of understanding the complexities of the machine by describing the components of the machine and their function in extensive detail. The judge awarded Knight the patent.

Patent model for Margaret E. Knight's second, updated paper bag machine from . National Museum of American History, Smithsonian Institution.

Pairing her technical skills with business savvy, Knight founded the Eastern Paper Bag Company of Hartford, Connecticut with a partner and then licensed her machine to the company. She negotiated an upfront payment of $2,500 with royalties accumulating to $25,000. Satisfied with the income, Knight became a full-time inventor. By the end of her life, she claimed 89 inventions and held over 20 patents in a variety of fields, including shoe manufacturing and engine design. Knight never concealed her gender when promoting her work, which won her acclaim among women's rights activists. Although not wealthy, she was able to live independently until her death in at the age of 76. Her last patent was awarded posthumously in .

Further Reading:

• 'A Lady in a Machine Shop,' The Woman's Journal, December 21, , p. 463.
• 'Career of Boston Woman Inventor Disproves Old Libel on the Fair Sex,' Boston Daily Globe, April 6, , p. 70.
• Anne L. MacDonald, Feminine Ingenuity: How Women Inventors Changed America, .
• Henry Petroski, 'The Evolution of the Grocery Bag,' The American Scholar 72, no. 4 (Autumn ): 99-111.

The History of the Paper Bag: From Invention to Utility

The paper bag is a simple invention; carefully constructed for the purpose of transporting items from one place to another. But where did the paper bag get its roots? How did it rise to popularity as a grocery bag, lunch bag, and retail shopping bag? Let's find out!

What did people use before the invention of paper bags? It seems they mostly used reusable and durable vessels like baskets, canvas bags, burlap bags, or woven bags. The first paper bags were made by hand, which meant they weren't very efficient or convenient to produce at a larger scale. It wasn't until the mid-'s that mass manufacturing of paper bags became a real possibility.

The First Paper Bag Machines

The Envelope Style Paper Bag

The initial rise of the paper bag was thought to be in . Schoolteacher Francis Wolle and his brother invented the first machine to mass-produce flat, envelope style paper bags. They patented the machine and then founded the Union Paper Bag Company. The invention of a machine that could mass-produce bags was a huge stepping stone in the widespread use of paper bags. However, these bags were very simplistic, flat, and could not hold a wide variety of items.

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Francis Wolle's envelope style paper bag manufacturing plant. Source

The Flat Bottomed Paper Bag

In , inventor Margaret E. Knight designed a machine that could create flat-bottomed paper bags, which could carry more than the previous envelope-style design. She got a job working at the Columbia Paper Bag company in Springfield, Massachusetts. She began to experiment with machine designs that could feed, cut and fold the paper automatically into a flat-bottom paper bag. Prior to this invention, flat bottomed paper bags were considered 'artisanal' and were hard to come by.

Once she had built a working model of her automatic paper-folding machine, Knight submitted for a patent on her creation. Knight was met with adversity due to a copycat who tried to claim her design as his own, but Knight ultimately won her rightful patent after litigation. Very few women held patents at that time, and her boldness and persistence to claim her own design was revered for women's rights.

Margaret E. Knight's design patent for her paper bag machine. Source

The SOS Style Paper Bag

In , Charles Stilwell patented a machine that made square-bottom paper bags with pleated sides, making them easier to fold and store. This style of bag came to be known as the S.O.S. bag, or 'Self-Opening Sack'. The bags would stand upright on their own when opened making them easy to load.

The bag machine patented by Charles Stilwell in to make these S.O.S. bags was a game changer for paper bag production. These bags were the inspiration for what later developed into handled paper shopping bags. SOS style paper bags are also still widely used today for pharmacies, food service, and grocery stores.

Charles Stilwell's patent for SOS paper bags. Source

Adding Handles to Paper Bags

In , Walter Deubener, a grocer in Saint Paul, Minnesota, noticed that his shoppers were having a hard time carrying their groceries home with existing bag options. He experimented by punching holes in a standard paper sack and threading cord through the holes to create handles. He and his wife, Lydia, made 50 of these bags to sell for 5 cents each and sold out right away. He decided to patent his invention and named it the 'Deubener Shopping Bag'. By , they were selling over a million bags per year.

Lydia Deubener with the 'Deubener Shopping Bag'. Source

In the Interstate Bag Company made a machine that could efficiently attach handles to paper shopping bags. Paper bags with handles later became the standard for department stores, and became cheap enough that stores could give them away for free.

The Importance of Paper Shopping Bags

Transforming the Shopping Experience

Paper bags made life easier for a lot of people. Parents could now send their kids to school with 'brown bag' lunches. People could transport their groceries and purchased items home more easily. Retailers could give their customers a better shopping experience by providing functional paper bags to carry their goods home. All of these advances in the mass production of paper shopping bags eventually led to retail businesses using bags for marketing and branding purposes.

Branding Paper Bags

By the 's, retailers were giving paper bags away for free for shoppers to carry down the street, and saw the opportunity for marketing. Many retail stores accented their bags with their logos or signature colors to help promote their branding. Carrying a branded shopping bag down the street became an important statement and status symbol. Shoppers soon became proxies for marketing as they carried branded shopping bags down the street for other consumers to view.

Bloomingdale's department store is one of the major icons of paper shopping bag branding. They debuted their 'Big Brown Bag' in , designed by Massimo Vignelli. Bloomingdale's has since created many iconic and memorable designs for their bags, using cutting edge artwork and marketing ideas.

Bloomingdale's Big Brown Bag. Source

Over the years, many popular brands have created branded custom paper bags with an iconic, easily recognizable look. Some shopping bags became status symbols for style and wealth. A branded paper bag became much more than just a way to get purchased items home, it became a fashion statement.

From its humble, utilitarian beginnings to it's transformative design and incorporation with marketing and art, the paper bag is a truly legendary packaging item. Retailers, restaurants, shoppers, parents, and everyone alike can appreciate how much more convenient life is thanks to the invention of the paper bag.

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