Most people do not really take the time to read about ink, but it is a topic with a long and fascinating history. Think about the roll ink plays in your life. Whether you own a printer or not, so much of what you do revolved around having printed material. If you did not have ready access to ink you would not be able to conduct your banking, run a business or send a postcard while you are on vacation. But this ready access to ink was not always the case.
For example in the middle ages the process of making ink was lengthy and required skill. It involved harvesting special bark, curing it for a year, soaking it for a week, boiling it and mixing it with the right ingredients at the right time. It was an almost alchemical process, and produced a powdered ink that was mixed with wine before use. This was higher quality than earlier inks used from ancient times onward, which were often based on suit and glue, or oil, and even had animal products in them. All of these early ink options were superseded by a varnish-like ink invented for the printing press, which would not smear as easily when inking pages.
These inks were very expensive and were designed for a market where only a very few people would be using ink or writing/publishing anything. That changed with the invention of the ball point pen. Suddenly writing was less messy. It was cheap and disposable.
This trend continued with the invention of the personal computer and with it the home printer. Suddenly everyone was able to use these devices and that democratized the market, bringing more producers to the industry and dropping prices significantly.