Harness: Leather vs. Synthetic

by Mari Lintin

Until fairly recently all draft horse and driving horse harness was made of leather. Leather looks good and smells nice, but maintaining it is time consuming. Leather is also heavy and, lacking a quality control department, varies in breaking strength.

Man-made webbing, also called "belting," overcomes some of these disadvantages. Webbing—which might be made of nylon or polyester, among other things—determines the harness's strength. A coating of plastic increases durability. The type of plastic used influences not only the look and feel, but also resistance to cuts, abrasions, dirt, chemicals (such as the acid in sweat), and moisture, as well as reaction to cold, heat, and sunlight.

The three available brands of plastic-coated belting are BioThane, Ohio-Thane, and Opu-Thane, all coated with polyurethane. Since BioThane was the first on the scene, and it is manufactured by the BioPlastics company, plastic-coated webbing in general is sometimes erroneously called "BioPlastic." BioThane recently became available in a new form called "Beta Series," coated with vinyl (instead of polyurethane) to give it the look, feel, and grip of leather for use as driving lines.

All synthetic materials are:
	Easy to clean with a sponge and water.
	Impervious to absorption (sweat won't cause rotting).
	Highly flexible in cold weather.
	Predictable in breaking strength.

Here, in summary, are the main materials used for making harness:

Leather

What it is: tanned cowhide.
Breaking strength: unpredictable.
Used for: all harness parts.
Advantages: traditional, heavy duty, looks nice.
Disadvantages: heavy in weight; has unpredictable breaking strength (the stronger you make it, by sewing layers together, the heavier it gets); requires high maintenance (frequent cleaning and conditioning).
Colors: russet, black.

Nylon

What it is: fabric made from coal, water, and air.
Breaking strength: 950 pounds per inch of width.
Used for: belting (all harness parts) and as the core material for plastic-coated belting.
Advantages: strong, elastic, highly flexible, extremely light in weight.
Disadvantages: highly absorbent; hair and dirt readily stick, causing chafing (must be kept extremely clean); cheap, slick nylon contains stiffening agents that cause rubbing and chafing.
Colors: many.

Polypropylene

What it is: similar to nylon, but lighter.
Breaking strength: 750 pounds per inch of width.
Used for: non-stress areas (back straps, upper spider straps, back pads).
Advantages: reduces harness weight, highly flexible.
Disadvantages: flammable.
Colors: many.

Plastic-Coated Belting

What it is: webbing (usually nylon or polyester) coated with plastic (such as polyurethane or vinyl).
Breaking strength: 1,000 pounds per inch of width.
Used for: all harness parts.
Advantages: looks like leather (all but Beta Series has the shine of patent leather) without the high maintenance; durable; resists scratching.
Disadvantages: does not handle like leather (the exception is Beta Series); not entirely acceptable in the show ring.
Colors: many.

Neoprene

What it is: synthetic rubber (wet suits are made from this material).
Breaking strength: 1,000 pounds per inch of width.
Used for: girths and breast plates.
Advantages: stretchy (sews like garment leather); doesn't chafe; resists oil, heat, light, oxidation.
Disadvantages: not strong on its own (used mainly as a lining).
Colors: black, grey, brown.

Mari Lintin is a Tennessee harnessmaker who has worked with both leather and synthetic. This article appeared in the Summer 1998 issue of Rural Heritage.