HP OfficeJet 6700

I installed the HP OfficeJet 6700 by switching it on an following the instructions on the printer's display. That's also how I connected it to WLAN. Then, on my computer I made sure cups is running and surfed to http://localhost:631. When I clicked on Printer -> Add Printer it appeared automatically as "Network Printer". I selected DIN A4 as paper size and double-sided printing Long-Edge (Standard). As driver I chose hpcups. As paper format I chose A4 210x297mm.