'Lock printer until my job is done' feature?

[Daniel Kasak]

Greetings.

We've got an Epson R1800 printer that I'm sharing out from my desktop.
The printer does A3 & A4, as well as glossy paper etc. We have lots of 
different people printing to it, and they want to print on different paper.

However, the printer only has 1 place to put paper.

Is there any way that a user can lock the print queue for everyone 
except themselves, then go and put their paper in the printer, submit 
their job, and then unlock the queue? Maybe this last step could be 
automatic after the job is completed.

Without this, you can have someone coming up to the printer to put their 
premium glossy paper in the printer, then go back to their desk to print 
something nice, but by the time they've gotten there, someone else has 
printed something that wasn't supposed to go on glossy paper. So each 
job ends up on the wrong paper, and everyone has to print again. Sad but 
true. Solution?

Dan