Recommendations for the above?

Only needs to be very small and basic, as little to go wrong with it as possible ideally. Need something to sit on our exam officers trolley that they wheel around with the exam laptops on, so that people can print their exams off no matter what room they're in. Only printing from notepad or wordpad (the laptops are locked down from doing anything else)

Never used any wireless printers before, so I'm unaware of how reliable they are and need recommendations