Printing multiple copies with Find Me printing causes printer to print incorrect number of copies
If you have set up Find Me printing with virtual queues using certain PCL5, PLC6 drivers (notably HP universal driver version 6.3.0 and prior), you may find that additional copies are being printed.
Problem
When you print a document and specify multiple collated copies, the actual copies getting printed at the device will always be squared. For example, if you specify two copies of a single page document, you will get four copies. PaperCut though will correctly count the number of copies and will record only two copies.
Cause
This is related to a printer driver setting known as the mopier mode.
When the mopier mode is enabled, a printer can receive one copy of a document, and print multiple collated copies. The number of copies required is specified via a PJL header tag in the spool file. For this to work, the printer needs adequate amount of internal memory to store the print job.
When this mode is disabled, the printer must be sent multiple copies of the print document in order to print collated copies.
Some PCL5, PCL6 drivers has this mode as a device settings option. And if you use one of these drivers in your virtual queue pointing to a NUL port, the driver cannot talk to the printer to know whether it is capable of supporting mopier mode. This will result in mopier mode being disabled for the virtual queue, even if the destination print queue can handle multiple copies.
Now, if a user prints a document with multiple collated copies to this virtual queue, the driver will convert the copies to separate jobs, and will also insert the header entry specifying the number of copies. Going back to our previous example, this means now the spool file has two separate jobs in the spool file and also has a header entry specifying two copies. Eventually, when this job goes to the actual printer, it will print out two copies of both the jobs, resulting in the number of copies getting squared.
Workarounds
The easiest option is to manually enable the mopier mode in the virtual queue. You can find this setting in Printer Properties > Device Settings > Mopier Mode. Setting this to enabled will fix the problem.
Another option is to use a different driver. Latest HP universal drivers (version 6.4.1 onward) do work as expected. Also, you can use a PostScript driver.
Or you can print uncollated, but that means you will have to rearrange the pages, which may be time consuming for documents with a a lot of pages.