In my several years working the retail sales in an Oriental Rug store, one of the more unusual (yet more common than expected) questions brought up by customers was the idea of whether or not an Oriental Rug could be used upside down, with the pile face down to the floor.
Perhaps this has a great deal to do with the natural intuition of buyers to seek out quality. Clients almost instinctively are drawn to better quality rugs. From the standpoint of an importer, collector, and hobbyists alike, a solid indicator of a well made carpet is whether or not a the reverse side is as sharp as the face of the carpet. A higher quality rug tends to have fewer discrepancies when comparing colors and design execution in this manner.
If not quality that the buyer is naturally drawn to, perhaps the preference may be a function of the increased popularity in antique style carpets within the last two decades or so. Rugs which have been used for many years with even wear tend to have a very thin pile, where knot heads may be exposed. This creates the appearance of a an upside-down rug, as once pile has worn away, the base of the knot head on the front of the rug is very similar to the knots seen on the reverse side.
May a rug be used upside-down?
It depends on the carpet. A rug with a pile height of 1/2" or more will rarely serve well inverted on your floor. However, there are such flat-woven rugs such as soumac weaves, which may in fact be used as reversible rugs. On the face of a soumac rug, you will find almost a crochet appearance of weave. On the reverse of the rug, the technique appears almost identical to that of a standard Oriental Rug: almost no distinguishable difference.
Below: Face Side of Soumac Weave
Below: Image of Reverse side of a Soumac Weave
Below: Reverse Side of a Piled Oriental Rug.
Conversely, we have seen beautiful oriental rugs seen both online and at local estate sales where the face of the carpet has almost been worn down to the foundation. From an collector's standpoint, a carpet with significant worn pile serves little investment use or long-term utility (for the most part). However, speaking from the buyers perspective, if any loose areas of the rug are fixed, the rug may have both added utility as well as aesthetic value in regards to the desired, albeit unconventional, orientation.
One must remember, that an Oriental Rug providing service upside-down will have significantly lower long-term durability. The reason for this is the knots on the reverse of a carpet hold the fibers to the skeleton of the rug known as the warps. The pile of a carpet is the extension of knots woven, protecting the longevity of your rug as this is the first part to wear away from use. If the carpet is used with pile side to the floor of a carpet for an extended period of time, not only will the pile become more matted, but also you will expose the carpet to premature wear, as there are no fibers to protect the knots of the reverse side other than the knots themselves. This use is not only reverse in orientation, but also opposite that of the intended function defined by the carpet's construction.
For more information on flat-weave rugs: Soumac's and Kilims