It is more expensive, and you would not have all Pantone colors available. But, as a printing house, when your customer like for example DHL tells you: "I need cardstock for 1 million envelopes printed with our logo, and it has to be PMS 2035 C red on PMS 116 C yellow." then you buy that exact inks from a printing ink manufacturer and print your cardstock - and if your paper was the correct brightness and the ink manufacturer has mixed the inks correctly, the colors will be perfect on the first attempt.

A lot of pantone colors are actually a mix of more basic pantone inks. For example Pantone 7416 U can be created by mixing 16,70% Pantone Yellow, 16,70% Pantone Rubine red and 66,60% Pantone Transparent white.

You still need to carry a lot more inks than just the standard CMYK, but its somewhat manageable. For large runs you just buy the pre mixed inks, but for smaller jobs you can mix them yourself.

You’re not quite envisioning the setup right. These machines use buckets/barrels of ink at a time. You pour the ink in.

And you don’t have one for each Pantone, but you can have a few tanks that you basically set up per run. So in the example where the guy is talking DHL, you might load it with black, pms 2035c and pms 116c. (I assume those are the official colors). When you’re done printing out the million envelops, you dump out any extra ink, and clean the Pantone ink out of the press, and load it with the correct colors for the next job.

Any commercial printing press will have capacity for CMYK ink plus multiple Pantone inks. A machine called a raster image processor reads say a PDF and generates individual printing plates for every color specified by the designer/client. A designer will apply Pantone color stickers to the ink jet or laser printout that the designer sends along with the digital file so that the print shop can prepare the printing plates and Pantone inks for the job. A machine like the automated paint mixers in a hardware store are used to mix up Pantone inks that a print shop doesn’t have on hand. There’s obviously an upcharge for custom inks which the cost is tacked into the bill. Clients will fire a designer for allowing the wrong Pantone colors to go to press. If a Pantone code is in the specification doc isn’t used by the print shop, the print shop will eat the cost of the mistake. There’s a “nobody got fired for choosing Pantone colors when it matters” mentality amongst designers and printers.