It depends on how big the UPS is. A laser printer is going to draw roughly 600 to 1200 watts, depending on how large it is. Most people DON'T plug them into the UPS; if you lose power it's pretty easy to clear any jam and wait until the lights come back on.
Laser printers can receive too much power from a UPS
Laser Jet
You can, provided that the laser printer has a USB connection and provided that the computer has a USB port and that the Operating System is capable of supporting the printer (it must have the proper "drivers" loaded)
The laser printer was invented in 1969 by Gary Starkweather at Xerox. The first commercial laser printer, the Xerox 9700, was released in 1977.
If you have an HP laser printer, I suggest you buy it directly from HP online store. I find it cheaper to get laser printer cartridges from them for my HP laser printer. If you have a different brand of laser printer, amazon is a good place to start if you're looking for a cheaper laser printer cartridge.
If the vellum is rated for a laser printer, it shouldn't be a problem. You do NOT want to use inkjet paper in a laser printer, or vice-versa.
RIP.
Laser printers use a drum and toner in the printing process.
Laser
If the transfer paper isn't made for laser printers, then the laser printer melts the paper. You can do major damage to your printer.
A laser printer uses a dry toner powder in a sealed cartridge.
Laser printer is the best printer on all these three categories.