Hemp rope

What is hemp rope?

Hemp rope (Dutch: henneptouw) is laid rope of the bast fiber of Cannabis sativa. The fiber is taken from the stalk by retting, is rough and hairy, and takes on a lot of moisture. That combination of stiffness and moisture uptake sets how the rope sits in the hand, how it smells and how long it lasts.

Where the smell and the stiffness come from

Both come from the way the fiber is taken from the plant. Zimniewska describes in her review article in Materials six routes for freeing hemp fiber: dew retting, water retting, osmotic degumming, enzymatic retting, steam explosion and mechanical decortication. She notes that osmotic degumming yields soft, long fibers without the smell that is typical of water-retted material. The smell of a fresh bundle is therefore not a mark of quality but a trace of the production process.

The stiffness is in the chemistry. Lignin makes the cell wall stronger and stiffer, lowers the ability to take on moisture and slows breakdown by micro-organisms. The more of it remains after retting, the firmer and rougher the strand feels.

What the rope does to the skin

Moisture changes the behavior. According to the same review, hemp fibers take on a lot of moisture and swell as soon as the cell wall gets water in it. A knot that gets wet from sweat or from a bath sits tighter afterward than it did, and that is exactly the moment you want scissors instead of patience.

What you buy and how you keep it

Read the label, not the word on the packaging. Langman Touw sells its natural rope under the name Hennep Touw and lists in the same table that the material is flax, one hundred percent flax yarns, with moderate abrasion resistance. Jute too is sold widely as hemp. Anyone who really wants Cannabis sativa asks for the fiber type and not for the product name.

With natural fiber, maintenance is a real cost. The same manufacturer names tarring as the classic treatment for rigging lines on tall ships. In the rope scene it is common to break in bundles and care for them with oil; there is no publication for that which counts as a source, so read it as custom and not as prescription. What is certain: store it dry, and a strand that frays or goes limp comes out.

If you’d like to feel hemp rope around you for once without having to buy and break in a bundle yourself, that belongs with a BDSM date.

Sources

• Hemp Fibre Properties and Processing Target Textile: A Review. Zimniewska, Materials 15(5), 1901, 2022 (Institute of Natural Fibres and Medicinal Plants, Poznan). Supplies the six extraction methods, the finding that osmotic degumming yields fibers without the smell of water retting, the role of lignin in strength, stiffness, lower moisture uptake and slower microbiological breakdown, and the high moisture uptake with swelling of the cell wall.
• Jute. Wikipedia. Supplies the botanical distinction from hemp: jute comes from the genus Corchorus in the mallow family, with fibers of one to four meters, off-white to brown.

Related terms

• Bondage. The overarching term hemp rope falls under as a material.
• Shibari. The Japanese rope tradition this rope is the classic material for.
• Asanawa. The same material under its Japanese name, with the sizes and lengths common there.
• Hempex. The synthetic rope that imitates this material and takes the maintenance out of it.
• Friction. Why a rough fiber lets a wrap hold without a knot.
• Abrasion. What happens when that same rope moves over the skin.
• Bight and double column tie. The first things you do with a strand.
• Jute. The other natural fiber, from a very different plant, and the one that most often passes for hemp.
• Rope. How a strand is built up, apart from which fiber is in it.