How do I setup a printer on a wifi network with an airport?

Is the printer wifi enabled?

If so did you read the instructions for setting up wireless printers with Macs??

http://support.apple.com/kb/ht3500

http://support.apple.com/kb/PH11387

What is the problem you are having??

The more specific the question the easier and more specific we can make the answer.

For a general question the above documentation is the best we do.

I'm having the same problem. I recently added an Airport network. The printer works fine in my old non-Apple WIFI. In airport utilities, the add printer is grayed out. (I did read the instructions) I want to use Airport for Time Capsule backup. My printer is a Canon MG5320. The printer sees the Airport network, accepts my password, and thinks it is in the airport network. My System Preferences Printers/Scanners/Add cannot see the MG5320. Yes, I waited about 10 minutes for it to show up. I reconfigured back to my old WIFI and it worked fined. I'm running OS X 10.10.4 and have downloaded the latest drivers from Canon.

If you haven't already, please try going through the following Cannon wireless setup document to see if it will help. The AirPorts do have limited WPS support and I would try that first.