'The German Ideology' contd.

What does it mean to say that "culture is materially produced"? As opposed to what?

Although my interpretation and response to this question may not be what Karl Marx was thinking during his time, here's my best shot.
By disecting this question, I can say that something that is materially produced means an object that is tangible and was made by combining several components together, either by man or by a machine. For example, a cake is materially produced by a baker, by combining ingredients such as flour, sugar, eggs, etc., just as a computer is materially produced by a machine combining parts such as the hardrive, the ram, the motherboard, etc.
Websters Dictionary defines culture simply as: the customary beliefs, social forms, and material traits of a racial, religious, or social group. In reference to the question, one might wonder how can such a thing as "culture be materially produced", if it is not tangible, nor created by man or a machine. In my opinion, culture is something that naturally exists in every society. To give a simple example, when the U.S. was bombarded by thousands and thousands of immigrants in the 1920's, each family brought along with them their own culture. The Italians continued speaking Italian and practicing Catholicism, just as the Germans continued speaking German and practicing their Protestant religion. From this, the American culture was born, which I would describe as extremely varied, because as I said, we've got Italians and their culture combined with Germans and theirs, etc.
What Marx might have intended by saying that "culture is materially produced" is that in a communist society, since no one has their own entity and everyone is equal socially and economically, they must create their own culture, because it simply does not exist.