Of course I am not assuming that. To illustrate what I am actually saying, here is a short story:
A man takes a look at the pen in his hand and wonders, "How is this ink made?" Before long, his mind wanders and starts wondering what types of naturally occuring inks there are and what they are like.
He postulates that the ink in his pen, since the company that made it has always used the finest ink for their pens, has come from a quality source.
He then looks on the Internet to find that there is indeed no naturally occurring substance that rivals the ink contained in his pen for quality and lasting use.
So he takes stock of what he sees, and makes an inferred assumption that the ink in the pen was made, and was not just harvested as is from the earth or some other natural source.
Now, mind you, the guy's assumption that the ink in the pen was created and not just harvested could be wrong, but all the evidence so far points to the fact that it was indeed manufactured.