Weedmat is an outdoor weed barrier fabric made specifically to stop weeds growing.  It creates a weed barrier that prevents light getting to the weeds thus killing them in a natural way.  Weed barrier cloth as it is also known is a natural alternative to weed killing chemicals.  Benefits of weed mat fabric include that it allows air and water to permeate the soil but not light.

Weedmat

There are different grades of weed fabric or weed matting and you should consider if you want to put the weed block fabric on top of the soil or cover it over.  If you plan to just lay the weed mat on top of the soil it should be UV stabilised, that is, it should be treated with a UV inhibitor substance so that it does not break down in the sun.  Premium weed mat is UV treated so it can simply be laid on top of the soil and will last for a long time.  If you plan to cover or bury the weed mat fabric under soil or stones then you can use a cheaper grade of weed barrier fabric that is not treated for UV degradation.  You can purchase both the premium weed mat and the standard grade weed mat from Shade Australia.