Carpet, Shading, Pooling, Watermarking, and Pile Reversal:

Shading, pooling, watermarking, and pile reversal are commonly used terms which are basically one in the same. This condition is an unexplained phenomenon that can occur in all pile fabrics, including upholstery materials. It may occur in traffic lanes, or in areas where no foot traffic occurs.

The actual cause of shading is a difference in light reflection from the surface of bent fibers, which appear lighter in color, compared to the greater light absorption and darker appearance of the more vertical oriented fibers.

Shading, pooling, watermarking, and pile reversal  most often affects plush carpet, including woven wool or polypropylene (olefin) fibers.

Characteristic patterns vary; some are snake like lines weaving around furniture and down hallways, others may be circular in shape. Some areas of shading may be marked with a "ridge" like irregular shaped line.

Shading is often found in establishments such as casinos or luxury hotels who have plush style carpets with coordinating insets and borders; the shading often crosses the seams of borders and patterns of different style and colored carpets.
In larger installations it is easy to see that the condition is not affecting one carpet, but an entire area. In homes, shading can be found crossing the seams at doorways to rooms with a different style and manufactured carpet. These examples show the condition is not related to manufacturing.

Shading, pooling, watermarking, and pile reversal is not a condition of wear, and does not represent a loss of surface pile or pile texture, therefore, this condition is not considered to be a manufacturing defect.
 

Circular Pooling	Random Pooling