Dye lots are guaranteed to match for yarn placed in a single order at YarnSupply.com. If we have differing lot numbers we will contact you before sending your order to verify that you need all of the same number. Exceptions include: yarns that are specified by the manufacturer as not dyelotted and discontinued or clearance yarns. You may receive differing batch numbers on manufacturer specified non-dyelotted yarns. We cannot guarantee matching numbers on clearance or discontinued yarns. What is a Dye Lot?