The range of raw materials includes many different material types and forms such as pellets, pigment pastes and powders, from opaque to translucent or transparent. The requirements on color measurement and sample preparation are particularly challenging because of the extreme diversity. Lot-to-lot color consistency is an important indicator of quality and can only be achieved, if the measurement results are repeatable and reproducible.
The ultimate manufacturing objective is to consistently and confidently sell their end product to a customer. Therefore, the product needs to be checked prior to shipping, to ensure it meets the agreed upon color and appearance tolerances. If the color is off specification, it will have to be reprocessed and potentially be sold at a lower price or even needs to be discarded. Therefore, incoming quality control of the raw materials is essential. Tight lot-to-lot variation is a pre-requisite for minimizing rejects.