Composition of a Rope

A Note on Twisted vs Braided

Braided ropes are far smoother than twisted ones, which means that they do not hold knots in the same way. Whilst braided rope can be used for bondage - particularly fusion and Western style - it is not advisable for anyone other than very experienced riggers, able to adapt ties and knots to its properties, to use it for Shibari. 

The following description therefore only relates to twisted rope. 

The Yarns

Yarns are made from short fibres twisted together. Longer fibres tend to produce a stronger yarn.

Ply

One strand of yarn is referred to as a single ply yarn. If we take two of these yarns and twist them together this creates a double, or 2-ply yarn. For very fine materials such as silk, it is not unusual to have a 36-ply yarn. The greater the number of ply a yarn has, the stiffer it will be: however with very soft yarns - bamboo, for example - having a 36-ply yarn may still result in a softer final rope than a single ply jute rope.

For Shibari, hemp rope tends to be made from 1-ply yarn, whilst jute rope is made from either 1- or 2-ply. Both of these options have advantages and disadvantages. 

Double ply rope is slightly stiffer than single ply, and not quite as strong. It is however resistant to abrasion, and less prone to high-stranding. Some people have a preference for the appearance of 1-ply rope, while others struggle to spot the difference.  

The strands

A strand is made from a number of yarns twisted together; three of these strands are then twisted together in the opposite direction to make rope. 

Why three strands?

Rope can be made with any number of strands. The reason three-strand rope is the most common type is because it allows maximum contact between the strands, and this in turn means it is the strongest. If we make a two-, three-, and four-strand rope, all 6mm in thickness, that three-strand will have the most yarn - and the more yarn we use the stronger the final rope will be. 

The lay

The lay of the rope describes both the direction the strands are twisted and how tightly this has been done. 

Direction of lay

When the strands are twisted together to make rope, they can either be twisted together to the right (clockwise) or to the left (anti-clockwise). Rope twisted clockwise is referred to as Z-lay, rope twisted anti-clockwise S-lay. Some wide ropes traditionally used in shipping are made by combining three smaller diameter Z-lay ropes to create a thick, S-lay rope. 

Ropes made from natural fibres are slightly stronger when made with a Z-lay, and when coiled it naturally coils in a clockwise direction. While the difference in strength is very minor, the way in which the rope naturally sits can be a far bigger issue, as can how knots sit on the rope. When you are used to using rope of one particular lay, it can feel very unnatural to use a rope of the opposite lay.  

I am able to make S-lay ropes by request as a custom order, but as standard all the ropes I make are Z-lay - this is the most widely used rope lay for ropes under 16mm