Hemp is the hippest kid on the paper block. But beyond the obvious – it makes for a fabulous paper story – there are other factors you want to be aware of before diving deep into these new paper options.
While we like to think we discovered something brand new, hemp was actually widely used in paper making across the world in the 1800s, but declined in the early 1900s as hemp production and trading ran afoul of narcotics laws.
With the legalization of hemp by the 2018 Farm Bill, we are seeing more and more mills offering printing and packaging grades that include varying percentages of hemp. Here are five things to keep in mind about hemp and hemp papers.
- Hemp Grows Very Fast. It is an herbaceous annual plant with a single, straight un-branched hollow stem that grows over a four- to five-month growing season to a height of 3 ft. to 16 ft. (1m to 5m). Compare that to trees which take 20-80 years to grow sufficiently to use for paper making. So theoretically one acre of hemp can produce as much paper as four to ten acres of trees over a 20-year cycle.
- Hemp Offers Extra-Long Fibers. Compared to wood fiber, hemp offers a four to five times longer fiber, which results in very strong paper. Unfortunately, the paper industry’s processes have been optimized to turn wood pulp into paper and so do not work well with the extra-long hemp fibers.
This is one of the reasons you see many paper offerings containing up to 10% hemp. Mills with more mature paper making machines are able to produce papers with up to 30% hemp.
With one of the oldest paper making machines in use, Germany’s Gmund Paper has been able to modulate their machine to work with these extra long hemp fibers and thus can offer papers with higher hemp content. (Pssst, they are even working on a 100% hemp sheet!)
- Hemp Fiber is Thicker than Wood Fiber. The thicker hemp fiber contributes to an overall beefier feeling sheet at a lower weight. A 320 gsm sheet, for example, feels like a 400 gsm one. (And we do love a hefty feeling sheet, don’t we?
- Hemp has a Lower Lignin Content than Wood. Lignin is the substance in plants that holds the cellulose fibers together – it’s “the glue,” so to speak. In the paper making process, lignin has to be removed from the pulp to prevent the paper from discoloring and deteriorating rapidly. Hemp contains 5% to 24% lignin, whereas wood has 20% to 35%.
- Hemp is More Expensive than Wood and Cotton. Currently, most of the hemp used in U.S. paper making is imported from Canada or overseas, which greatly increases the cost.
While the U.S. grew more than 75,000 acres of hemp in 2018 – and that number is rising rapidly – most of that hemp was grown for CBD oil or hemp body-care products.
And as a great conversation starter at your next Zoom cocktail party or BBQ, let me add this:
- Only the Male Hemp Plant is Used for Paper Making. Hemp is a dioecious plant, meaning that individual plants form female or male reproductive organs. In the hemp world, female plants are worshipped because it’s the female flowers that are used to extract CBD, and are harvested and consumed by cannabis connoisseurs, both recreationally and medicinally.
The male hemp plant, on the other hand, is mainly used for fiber production and breeding purposes. (Insert your own joke here).
While the overall benefits of hemp-based papers seem ample, we do not have enough hemp plants available to replace all of our wood-based papers, even if we wanted to. In addition, the technology for mass-producing the different kinds of paper we use are still being perfected.