Pigment Yellow 168 P.Y.168 is a calcium pigment lake and chemically closely related to the P.Y.61 and 62:1 lakes. It has been commercially available for some years, but has as yet gained only regional importance. It provides a clean, somewhat greenish yellow shade somewhere between the shades of P.Y.1 and 3. P.Y.168 is used in paints and plastics. The pigment exhibits good fastness to aliphatic and aromatic hydrocarbons; but it shows only limited resistance to alcohols, esters, and ketones. It is largely acid and alkali resistant. P.Y.168 is not fast to overpainting. It is used in inexpensive industrial finishes wherever the application requirements, especially as far as lightfastness and durability are concerned, are not high. P.Y.168 shows good migration resistance in plasticized PVC, but its tinctorial strength is relatively poor. In transparent colorations, its lightfastness (0.1% pigment) is equal to step 6 on the Blue Scale; at 1/3 SD it corresponds to step 5. In HDPE, the pigment affects the shrinkage of extrusion products, which is typical of azo pigment lakes of this class. P.Y.168 is recommended especially for use in LDPE.