Examination and my experience of over 35 years in the flooring industry have proven the following. In the application of various carpet and rug types or styles, the most notorious for exhibiting pile reversal problems are Saxony and Plush (also known as cut-pile), followed closely behind by Textures, and we must not neglect this less likely result from a Cut-and-Loop (or Sculptured) carpet. By far, the type of carpet (or rug) that is least likely to exhibit pile reversal, would be a Cut-Berber. Also known as Frieze. Although this type of carpet is technically considered a cut-pile, the construction of tight twists that tend to lay in differing directions, makes this type of soft surface floor covering the least likely to ever experience any type of pile reversal. Even if there were a pile reversal problem it would not be evident to even a trained professional. For those who are unaware, pile reversal is not considered a defect in carpet or rug construction. If it occurs in a Plush style carpet, it will be extremely notable as what is considered "pooling" or "watermarking". As this problem is not considered a defect, it is not covered by any warranties from the manufacturer. This can be most unsettling for a consumer that is unaware of pile reversal. I assume that this question has come up as a result of such an experience by the person who posed it. Pile reversal is not an overwhelming problem in the flooring world. Your chances of getting a carpet or rug that exhibits pile reversal is rather slim. But if you are one of the unlikely few who end up with an area of "watermarking" (so called because it looks like someone poured water over an area of your carpet that has caused the fiber bundles to lay in a direction that is opposing to the surrounding fibers) in your brand new carpet, you certainly want to avoid any chance of the problem in the future. Especially if you fought with the manufacturer over what you considered must have surely been a defect that would be covered by the warranty. To avoid any chance of pile reversal you may consider buying a Cut-Berber or Frieze carpet. Not only will pile reversal never show, the nature of this style of carpet makes it an excellent choice for high-traffic homes and ease of care and cleaning. The big difference in durability comes from the fact that you walk almost entirely on the sides of the fiber bundles instead of the top of fiber bundles in a Plush or Saxony. I hope that this information will help you choose a style of carpet that you will be happy with for many years to come. Review/ Report by Chazb at http://RugRunnerBiz.com where you will find a selection of Fine Wool Area Rugs and Home Decor Items.