Apply%20from%20the%20base%20of%20the%20neck%20to%20the%20tip%20of%20the%20chin and then massage any excess cream over the décolleté area. This instruction typically applies to skincare products like creams or serums for the neck and chest area. A 50% concentration of a particular ingredient means that it is present in the formulation at a relatively high level, usually indicating its importance or efficacy in the product.