Preferences -> Default Printer is useless

Thanks for your report; assigning to system-config-printer. Please take a look at https://wiki.ubuntu.com/Bugs/FindRightPackage and try to assign the bugs you file to a particular package in the future.

Marking as Confirmed. Default Printer is from legacy Linux printing systems where you could designate a default printer instead of typing out a long device name string. It works similar to the default printer selection in Windows. The difference is you have to select a default printer. If you don't then nothing happens.

Go to a browser and type:

http://localhost:631/printers/

You should see a list of defined printers. You can select default printer by clicking "Set as Default". After that, then try using default printer in gnome applications.

I agree with you it's confusing to a new user. A dialog should come up that says no default printer is defined would you like to pick one?

It DOES NOT work!

From the CUPS web page (http://localhost:631/printers/):
Dell_3100cn
LaserJet-4200 (Default Printer)

And from a command line: lpstat -d
system default destination: Dell_3100cn

It's REALLY ANNOYING!

How am I supposed to change my default printer?

There is a difference between the system default and the user default. The 'preferences' application probably sets the user default, whereas the printing configuration tool sets the system default.

Hm. And the solution is?

For GTK+ to use the user default -- I believe current GTK+ does the right thing (it does on Fedora rawhide anyway).

As said by Tim there is a difference between the system default and the user default printer.

> Selecting a default printer under Preferences -> Default Printer does not do anything.
Yes it does set the user default printer in ~/.cups/lpoptions

> Going to Administration -> Printing shows that no default printer has been set.
That's because no system default printer has been set. In system-config-printer users part of the lpadmin group (normally first user) can set the system default printer in Ubuntu.

> Opening gedit and going to File -> Print doesn't reflect a default printer being said either
> (PDF and PX-A620 show in the printer list and neither is selected).
gedit selects the user default printer here on Ubuntu 8.04.1 LTS, so Preferences -> Default Printer is not useless since it always sets the user default printer.

> If there is supposed to be a difference between default printer in the two apps
> ("Default Printer" and "Printing"), then it needs to be made clear (for example:
> if Preferences -> Default Printer only applies to the user, then it needs to say that.
> If Administration -> Printing applies system wide, then it also needs to say that).
> If the default printer in "Default Printer" and "Printing" should be the same, then what is
> the purpose of "Default Printer"? It would just be redundant.
Perhaps the description "Default Printer" in system-config-printer should be changed to "System Default Printer" to make this clearer to the user.

I checked in Ubuntu 10.04 and 10.10:
Preferences > Default Printer has been removed and system-config-printer now asks if you right-click "Set as default" on a printer if you want to set it as the system-wide or user default printer. The first printer that is added automatically becomes the system-wide default (green check mark icon).
gedit's File > Print selects the user default printer if available and otherwise the system wide default printer.

So I think this solves your problem, therefore closing as Fix Released.
Feel free to reopen if you still see a problem.