A dye lot refers to all of the material dyed in a particular batch. In this phrase, the word lot is a designation of a fixed quantity and distinguishes itself from other lots or batches of material that were dyed or colored in other lots or batches.
Manufacturing quality controls are created to sustain consistent factory conditions so that each run or batch looks the same. However, it is impossible to guarantee that there will not be some color shift from one lot to the next. All flooring products that are synthetically colored or dyed are subject to dye lot differences. Therefore, individual lots are commonly identified by a number which is called the dye lot number.
For example, Shaw made a carpet named Chance Encounter in the color Soft Ivory. One roll in particular had the dye lot number S92751, which was printed on the shipping ticket and our order confirmation. When a commercial carpet installation requires numerous rolls, we have a greater concern over the potential of dye lot differences. A dye lot difference will typically be evident by one roll appearing darker or lighter. The difference can be problematic if carpet from two rolls (with dye lot differences) are seamed together, which creates a side-match problem.