Something I only discovered after visiting the Apple Shop yesterday, is that the AirPort built into in my newish iMac, is a receiver only. To make a wireless printer work, it has to receive an Internet signal. This means either:

A transmission directly from the wireless router that brings the Internet to the Mac. 
or
A transmission from a separate wireless router connected to the Mac, such as Apple's AirPort Express.

I do not have a wireless router for the Internet, so my printer will not work except via USB.
Brian, I guess that you are connected to the Internet via a wireless router. If this is so, it does not matter if your iMac is on or off as her printer is receiving a signal directly from the wireless router.

If this is all rubbish, my apologies, but please tell me.

Doug

Who is broadening his sphere of ignorance!  


On 12 Apr 2011, at 22:40, Jon Johanning wrote:

> On 4/11/11 10:30 PM, Brian Ferguson wrote:
>> However, it appears that her iBook uses its Airport link to my iMac and then to the printer. I assume that if I turn off the iMac she cannot print.
>> 
> I wouldn't swear to this, since I am no networking expert, but I think that if the iBook, iMac, and printer are all on one network, it wouldn't matter if the iMac were off -- but the Airport has to be on, of course. Try an experiment and see.
> 
> Regards,
> 
> Jon Johanning