How to Value an Oriental Rug

Learn the number of knots per square inch from a catalog or dealer. The more knots, or stitches, per inch, the tighter the weave and carpet design and the higher the value. Over 200 knots per square inch is recommended, but 500 is better. Some of the highest valued rugs have as many as 1,200 knots per inch.

Be sure the carpet is made of natural fibers, not synthetic ones which have far less value. Over time, fibers like silk, wool and cotton won't fade or weaken and they absorb color dyes well. Study the fringes of silk Orientals, the highest-value Orientals. If the fringes are not an extension of the weave, but sewn onto the edge of the rug, it is likely artificial silk.

Test a chosen rug to be sure it is hand-made. Machine-made rugs have no investment value. Perform two tests. First, study the back of the rug. If the design is as clear as it is on the front, it is likely hand-made. Second, bend the rug back on itself to expose the base of the pile. Knots at the bottom of the tufts, or pile threads, confirm that it is hand-made.

Be sure a rug is made of vegetable dyes, not aniline, a liquid-based nitrobenzene used to make synthetic dyes. Vegetable-dyed rugs are much more valuable and have a long life. Colors made with synthetic dyes will fade to different colors and even disappear. Bend back a white or cream area of the rug. Colors appearing at the base indicate that synthetic dyes were used and have run.