Ideas

Sometimes you need to store more complex information about a product, information that will be shared between many products.

Let's say that a product can be made of a fabric, where the fabric itself has many fields. Products therefore need to be able to point to a "supporting entity", a fabric instance. Many products can point to the same supporting entity, you do not want to duplicate thte fabric information on all products.

Supporting entites should have fields (and a field template), but they are not products. They do not have article numbers, Urls, published on channels, prices etc.