Pile Reversal and Shading

pile reversal

Pile reversal and shading are common carpet problems that can occur to any carpet with a cut pile element. However, it is most often observed in smooth surfaced, densely constructed, plush-style carpets. It can cause areas of a carpet or rug to appear lighter or darker than the rest of the carpet.

This phenomenon’s occurrence is random, and its causes are largely unexplained. It is difficult, if not impossible, to predict or prevent.

carpet pooling


Pile reversal creates a permanent change in the carpet’s appearance caused by the difference in the way light reflects off the sides and tip of a yarn as the pile lays in different directions. Shaded areas appear lighter in color from one direction and darker from another direction.

Pooling or watermarking are other terms for this phenomenon and can occur in both trafficked or untrafficked areas. Pooling or watermarking might develop on a carpet made with any fiber(s) or manufacturing process. Once the condition has developed, it cannot be removed permanently.

A carpet exhibiting watermarking might look as though water has spilled on sections of the carpet, hence, the term “watermarking.” While it looks like something has spilled on the carpet, water has nothing to do with it; it is a phenomenon with no known cause or permanent fix.

Why the carpet pile, which lays uniformly in one direction when installed, changes direction permanently, is often a mystery. It can also appear that the carpet has lost color in the affected areas, but after close examination and testing, you’ll discover that no color loss has actually occurred.

Traffic-related pile reversal

In many installations, the pile reversal direction is predictable from the pattern of foot traffic. Carpet pile is pushed away from turning traffic and toward the sides of a corridor.

When any form of pile reversal takes place, there is little which can be done to return the carpet to its original appearance. Pile lifting, steaming, brushing, or vacuuming might create some temporary appearance change; however, this change is only at the top portion of the tufts, and the pile will eventually return to the reversed position.

All these phenomena are characteristic of a textile floorcovering; they are not manufacturing or installation related.


Carpet and Rug Institute (CRI) Technical Bulletin:
Pile Reversal–Watermarking Shading (April 19, 2018),
Pile Reversal–Watermarking Shading Technical Bulletin (www.carpet-rug.org).

Mark Violand

Mark Violand has been in the cleaning and restoration industry more than 40 years. He is an IICRC-certified carpet inspector and approved instructor. His reputation precedes him as Northeast Ohio’s go-to floor covering inspector, working for carpet, resilient, wood, and laminate manufacturers, and floorcovering retailers. He teaches the Carpet Cleaning Technician, Commercial Carpet Maintenance Technician, and Carpet Repair and Reinstallation Technician courses and serves as chairman of the ANSI⁄ IICRC S800 Standard and Reference guide for professional Inspection of Textile Floorcovering. Contact him at [email protected].

Follow Mark Violand

Related Posts

Share This Article

Join Our Newsletter

Expert Videos

Popular Content


Concrete Wars: Go to Battle With Ameripolish on Your Side

CoreLogic Straighttalk 800

Efficiency Meets Innovation: CoreLogic Revolutionizes Water Damage Restoration With Mitigate


ServiceMonster: All-in-One Client and Job Management Platform Built for Carpet and Floor Cleaners

Masters in Restoration Pricing & Documentation

Masters in Restoration Pricing & Documentation: How to Turbocharge Your Restoration Project Strategies

Erin Hynum

Revolutionizing Restoration: Introducing the DryMAX XL Pro Dehumidifier


Has the increase in remote work made booking residential cleaning appointments easier than before the COVID-19 pandemic?

View Results

Loading ... Loading ...