Printer sharing in OS X is a convenient feature that turns your computer into a print server and enables you to share any printer configured on your system with other computers on a local network. This is great for setting up non-networked printers (in other words, USB printers) for use on the network.
However, unless you set up a password, then the shared printer can be accessed by anyone. In a work environment it may be beneficial to have a password so that random people setting up printers on their systems will not inadvertently print to your printer.
The first step in setting up a printer password is to set up the shared printer. To do this, follow these steps:
Go to the Sharing system preferences.
Check the Printer Sharing service.
Select the service and check the printers you wish to share.
Now that the printer has been shared, the next step is to specify the users who will be authorized to access the printer. This can be individual user accounts on the system or network-only accounts (sharing accounts), and can also be groups that contain both of these account types.
To specify an account, follow these steps:
Select the shared printer and click the plus button below the user list.
In the window, add local user accounts or networked users, or you can click the New Person button to create a sharing-only account. With a sharing-only account you can set up a generic printer log-in account for all network users, which may be more convenient than creating individual log-ins for each user.
With the accounts (or groups) created and selected, click the Select button to add the accounts to the list of users.
When the accounts are added, the system will set the Everyone group to No Access, thereby requiring people printing to supply credentials. If you switch this back and give Everyone access again, then any groups you added will disappear from the list.
The printer is now set up to be shared only by the specified accounts. While you can do this for individual printers, if you have, then you can share those as well, allowing users to print to any available device in a group of printers.
If you have a printer connected and wish to use an Open Directory or Active Directory Kerberos authentication scheme, Apple has a new knowledge base article about configuring the system to use this authentication method rather than its local directory. You can read more about this setup here.