Here’s some advice for collectors from two experts in the field.
Determining a hooked rug’s age can be challenging–even for dealers. Newish rugs, if worn and faded, can look old, while truly old rugs, if well stored for a long period of time (as good ones often were), can look new. Some tips that might help: If the rug material is synthetic, think circa or post 1930. And if the design features primary colors and cartoonish objects and figures, it’s probably from the 1920s or ’30s. Repair patches on the back or tightly woven linen backing often indicate rugs that are decades older. From Country Living
An antique rug is usually considered as one made between 1775-1825. From 1825 to 1875 collectors identify them as “early,” while “late” covers the years from 1875 to 1900, and “modern” are those made within the last fifty years. Age in a hooked rug is revealed to some degree by pattern and subject, but more by the use of a hand-woven foundation material of cotton or linen, as well as the presence of vegetable dyes. The linen foundation was soon superseded by burlap, so that while rugs containing linen bases are definitely antique, few are to be seen. From Old and New