Black stripes under the door

01

Cause

Dust particles from the air.

02

Explanation

The door closes on the carpet. The draught running underneath the door streams through the carpet and filters the small dust particles that become embedded in the fibres.

03

Solution

For synthetic yarns, rinsing with water and a correct cleaning agent (such as James Cleanmaster) using a spray extraction method will help. Check out the companies James recommends to have your carpet or furniture professionally cleaned here.
Yarns mixed with wool or made from 100% wool cannot be cleaned. Cover the carpet area with a strip of (stainless) steel, or place a strip of a darker coloured carpet such that any discolouring is not visible anymore.