The accounting department accounts for the finances of the company.
The purchasing department purchases or arranges contracts often by competitive bids, for goods and services.
The IT department, the Information Technology department, sets up, installs, maintains, and upgrades the data processing equipment, the computer systems, hardware and software.
Printing is an administrative function, a responsibility of the administrative staff, or person responsible for admin functions. It could be in the reproduction (REPRO), or mail room in some companies. It also could be jobbed out / farmed out / contracted for from an outside agency by the purchasing department, but not physically done by them.
That is normal business; unless the company management assigns it as an additional duty to some department or person.