I'm just wondering: What is the industry standard for printing the interior pages of a novel or a book that contains only black text and B&W images? Do you print using CMYK but only use 100% black, or do you use a Black Pantone? I'm guessing Pantone would give a bit of a richer feel to the text, but CMYK is probably cheaper?
The initial assumption in your question is very nearly correct; a black only print job would just use black ink and this is (sort of) like using just the K (black) from the CMYK set. Process Black, to use correct name for it.
However, not all black ink is the same. Ink is made up multiple components, including pigment (which provides the colour) and a medium to carry and extend that pigment. There is a balancing act involved in having enough pigment to produce the desired colour without using too much, because the pigment is the most expensive component.
There is also consideration required for the nature of the job being printed. Process inks that are being uses on screened images need to be very fluid and clean running in order to reproduce the dots in the image while a job that includes all solid shapes (like text) doesn't need to be quite so refined.
In addition, the printer will adjust the ink to optimise performance for things like press speed, impression, ink density and plate wear. The compromises that are acceptable will vary depending on the quality of the finished book. The difference between a hard backed first edition of an expected bestseller and a cheap paperback reprint of a shakespeare play are obvious in both the quality of the print and the paper used. There are lots of variables, all of which can be adjusted to hit a desired cost.
So in summary; black only, one ink, one set of printing plates.
A couple of additional notes that are relevant:
- It's highly unlikely that a Pantone reference would be used for printing text in a novel, unless something bespoke, artistic and expensive was being attempted.
- There are always exceptions to rules. For instance, if a novel had lots of images that needed to print very nicely then the images and text might be split and printed as two black plates - one optimised for the text and one optimised for the images.
I think that black is the standard for a few reasons. Obviously anything can deviate from the standard, but the main considerations are:
ink usage. For novels, the print runs can be between 100,000 or 1,000,000. So 1-color instead of some rich black of, say 10,10,10,100 "rich black" can be a 25% savings on on the ink volume.
clarity. If the text is screened, fine lines get dithered because of screen angles.
quality. If the registration is off a little, the text is muddled. Whether it is screened or line art in all plates, this will cause color halos which make reading difficult. Poor registration will also have a minor impact on perceptions of the publisher.
There are probably going to be cost considerations associated with the time-to-run the job: if you have one color, you might be able to run the job faster, and it eliminates some of the materials and time lossage associated with runnign a mutli-color job. I am no pressman though and I know some of these things run at ungodly speeds (3000 feet per minute; 100k copies per hour etc.)
My two cents.
Printing costs it is not all about ink, but the type of printer used.
If you are printing only one color, you most likely will not use a 4 head printer, because it is a waste of money.
A CMYK print costs arround 4 times more than 1 color print excluding paper, so you do not think in terms of a CMYK print using only the black channel.
The specific ink would not be the same as a Process black (the one used as k in a cmyk print) because this ink is semi transparent and printed alone gives a grayish look. There are several types of black, some called intense or deep black, some of them inclusive are cheaper by kilo and yields more because you use a thinner layer of ink.
This ink could or not be an "official" pantone ink.