Beta is one of the coatings produced by the US company Biothane. It is a soft and supple coating that is the most leather-like of their offerings. It has a matt finish and grain embossed to complete the leather look and is totally waterproof.
With a break strength of 450kgs per 25mm width and the ability to maintain its flexibility even in very cold weather, it's a brilliant choice for dog products.
We love biothane because of just how easy it is to clean. If it's a bit soiled you can give it a quick wipe with a cloth or for heavy soiling you can give it a wash with warm water and soap before leaving it to air dry.
Polyproylene rubberised webbing is soft and comfortable to hold. It doesn't absorb water the way nylon does and the rubber running through it makes for a brilliant superior grip.
Whilst not totally waterproof, polypropylene is very efficient at repelling water. Should your line get dirty, you can rinse it with warm water and soap which should have it looking as good as new.