Learn Finnish: Yritys painatti uuden esitteen. - The company had a new brochure printed.

The base verb is painaa (to press or to print). By adding the curative suffix -ttaa, we get painattaa, which means to have something printed by someone else. painatti is the past tense 3rd-person singular form of this derived verb.

Why are uuden and esitteen in the genitive-looking accusative case instead of the partitive?

This indicates a total object, meaning the action is completed and covers the entire item. The company had one complete new brochure printed, not just an unspecified amount of printing. For a single whole object in an active sentence, the accusative case looks exactly like the genitive (ending in -n).

What is the dictionary form of esitteen, and why does it have a double tt here?

The dictionary form is esite (brochure). Nouns ending in -e undergo reverse consonant gradation when case endings are added. The single t in the weak dictionary form strengthens to a double tt in the stem, and the final e doubles, creating the stem esittee- before adding the -n ending.

If we wanted to mention who actually printed the brochure, how would we add that to the sentence?