No, that is NOT what I am asking. We do a large amount of business with companies that require we send them a paper snail mailed invoice. Given the volume, its much easier to just click one button in OG and print them. WHMCS did not offer that last I checked. No, I' not talking about created a pdf and then opening it and printing it either...
I understand. It is definitely doable. http://forum.whmcs.com/showthread.php?3036-Mass-invoice-print-combine-PDF-files I think this link will help. I believe this is what you are trying to do?