The natural and variable change in color that occurs in an Oriental rug.
Abrash typically occurs for two main reasons
*Variations in different batches of Dye.
*Different batches of wool.
When a rug requires an additional lot of dye to be produced, the dye is not usually a perfect match. Often times the dye is all from the same batch, but the rug requires more wool, which means more sheep. Fascinatingly, Dye takes differently to wool, depending on the particular sheep. Also, when the wool is hand-spun, certain areas are spun more tightly than others, making that section less able to absorb dye. The result is a less intense color.
Although this makes the rug imperfect, it is the unavoidable variations due to human error that make the rug beautiful. In fact, Abrash is so well admired that it is not uncommon for a rug maker to purposefully create imperfections. It is also a cultural practice and sign of respect to God, believed to imply that “no one is perfect except for God.