Visual Color Change in Carpet: Shading and Tracking

Shading: When a carpet is manufactured the pile is steamed and set in a single direction. Once a carpet is installed natural directional changes begin to take place. These changes range from slight bending of the pile tufts, opening of the tuft ends (bloom) and compacting (crush). At times areas of the carpet pile will even take on a total reversal from their original direction. Most shading occurs in areas where you have repeated or pivotal foot traffic. Shading while not a real color change will often give the appearance of an actual change in hue. While the color change may appear real it is actually visual and due to differences in light reflection and absorption over a given area.

Shading is a broad term without total industry agreement as to how to define these areas. The definitions that we use in this chapter are those most commonly used by the Carpet and Rug Institute and the International Standards Organization.

Shading (Temporary Shading): A reversible localized change in orientation of the pile of a textile floor covering during use (sometimes described as normal characteristic of certain cut pile textile floor coverings).

The only true temporary shading are marks such as those left by footprints and vacuum cleaners! In reality, shading is almost always a permanent condition. The shaded appearance may be temporarily changed through vacuuming, steaming or cleaning but it will rapidly return once the carpet is walked on.

Traffic lane shading usually develops first in the higher and pivotal type traffic areas. The areas may look lighter or darker depending on the direction they are viewed form. When you run your hand across the pile it takes on a darker appearance in one direction and a lighter appearance in the other. This condition is normal and almost always permanent. Traffic lane shading is considered by the manufacturer to be a normal characteristic and not a defect.

Shading is a normal characteristic of cut pile carpet, especially those with a smooth pile such as velvet and saxony plush. Shading is considered an aesthetic quality of fine carpet and is not considered a defect. A person that finds shading objectionable should select a carpet with a denser construction, lower pile height, textured yarn. Examples would be textured saxony, frieze, and berber.

Vacuum cleaner marks, is temporary shading that is left on the carpet by the brush and/or wheels of the vacuum cleaner! These marks may be noticeable for a few minutes or a few days depending upon the texture and resiliency of the fiber. Most deep-pile and smooth pile carpets will show vacuum cleaner marks. A vacuum cleaner mark is considered a normal condition unless otherwise excluded under a carpet warranty. Vacuum cleaner marks are least noticeable on loop pile and denser cut pile carpet where the yarn has a tight twist and a textured appearance.

Footprints are temporary shading marks left by humans and animals walking across the carpet. They may be noticeable for a few minutes or a few days depending upon the texture and resiliency of the fiber. Most deep-pile and smooth pile carpets will show footprints. Like vacuum cleaner mark, footprints are considered a normal condition unless otherwise excluded under a carpet warranty. Footprints are least noticeable on loop pile and dense cut pile carpets where the yarn has a tight twist and a textured appearance. Printed carpet is also good at camouflaging footprints.

Tracking: A gradual change in appearance of a textile floor covering from edge to middle of a narrow band caused by repeated walking over the same area which may result in a localized change in pile orientation and may be irreversible.

Tracking may be seen as single or double narrow bands. Double marks often give the appearance of railroad tracks running down the middle of a hall or other repeated traffic area. Severe tracking marks are most commonly found at installations where the occupants shuffle their feet, have difficulty walking, or walk in such a way that the feet are regularly not lifted above the pile height. Like other forms of shading, tracking marks are not considered a manufacturing defect.