I brought a regular A4 inkjet printer ([https://www.epson.eu/en_EU/support/sc/epson-ecotank-et-4750/s/s1563 Epson EcoTank ET-4750) along, with lots of ink and paper. Nothing fancy obviously, but probably enough to print some fun signs or your train tickets.
How to
Contact me if you have something to print. Send me a PDF and the amount of copies you'd need. Also indicate whether one-sided printing on used paper (back side might have some school material on it) is okay. Otherwise paper will be 80g/m² 70% ISO whitness recycling I also have a bit of photo paper A4 and 10x15, so if there's a reason to use that just ask :)