Laser printers draw a large amount of power, so its preferable that they are not backed up as they will discharge the UPS battery very quickly.
Ink jet are slightly better on power consumption.
Best to connect the printers to the UPS additional surge protected outlets that do not provide backup power (the Ultima have a single light grey socket that is connected directly to the UPS mains input). If you do plug the printer into the outlets with battery backup power, the UPS backup time during an outage will be reduced.