I recently saw a couple of copies of my books and realized that the Tattoo Encyclopedia is now in its 11th printing and Ink is in its 8th. To find that out, I flipped open the front cover and found the printers key.
Of course, the printers key has a more descriptive name and one that will actually help you locate it: the number line. So, if you flip open your book, you’ll see the back of the cover to the left and the title page to the right. Turn the title page over and you’ll then see the copyright page. Somewhere on the copyright page you’ll find the number line, strangely resembling, of all things, a line of numbers. The lowest number – they aren’t always in order – is the number of the printing. As the number of printings goes up, the printers key gets shorter. For the second printing, for example, the number “1” will disappear, but all else will remain the same.

Copyright Page
So, in the example above, taken from Rites of Passage by Van Gennep, there is a red box around the printers key. This is the 13th printing of that book and it was printed in 1996.
If you’re thinking that the whole thing smacks of something archaic, you’d be right. This is a system that was born sometime after World War II, but more than that, it harkens back to the time of the Linotype slug.
Many people theorize that the numbers disappear because that’s the most foolproof way of amending the copyright page. You’re less likely to have an error if you’re just removing a number rather than trying to add one. While true, there is also the physical reality of the mechanism that was used to print books, starting in the late 1800s.
The Linotype machine (“line of type” machine) did exactly as the name suggests. It produced a single, solid, metal line of type. Each word in the line was assembled by an operator, using individual metal block letters and spacers, and then the machine would actually use molten metal to weld these pieces together into one single piece from which a single line of a book (or pamphlet or magazine or what have you) could be printed. It’s a process also known as hot metal printing.
The shrinking number line scheme, while also less likely to introduce errors, makes the least amount of work for the publisher. Instead of creating a new Linotype slug for the number line, the last (or outer) number in the existing line (the lowest number) could be filed off and the slug used again. It’s a wonderfully economic system. But I can’t help but wonder how the digital era of book publishing will change it. There is still the argument that it’s a method less prone to error, but what about the cost savings in ink when you stop printing all the numbers in the line and just print one?


If the example shown is the 13th printing, then what does the 01 00 99 98 97 96 mean? Every book’s number line/printers key is different. Is there a source which can explain all the different variations and how are editions indicated?
Thank you for your response.
Hi david, Those numbers are the last two digits of years: 2001, 2000, 1999, etc. The number 96 means it was printed in the year 1996. And yes, you’re right, every printer’s key is different. I don’t know of a comprehensive source for all the variations since it’s not really a matter of rules but of tradition and how closely individual printers want to stray from it. Thanks for your question!
Hello, I wonder if anyone can help me with the following notation:
30 29
20 09
The first line isn´t the problem but rather the second line – because the edition is a 2008 edition. I am assuming that it is the 29 printing (in 2009) of the 2008 edition of the work. Am I right? So why is the notation for the year presented like this 20 09 rather than 2009? By the way this is a McGraw publication.
Thanks for the help!
Martha
Hi Martha, Well that’s what it looks like to me–the 29th printing. Popular book!
Best, Terisa
I read on Wikipedia that “Sometimes, when the publisher outsources the printing to a contractor, there will also be a code for which printing company was contracted”. Is there someway to find out the printing company?
First Example (“032″):
ISBN 0-15-322922-5
11 12 13 14 15 16 17 032 10 09 08 07 06 05 04
Second Example (“DW”):
ISBN 0-618-59093-5
123456789-DW-14 13 12 11 10 09 08 07 06 05
Thanks for any help!
Hi Pacific, You know, I’m totally unfamiliar with that practice. Nor do I know how to see the printing company in the slug line. I find it strange, though, since virtually all publishers outsource their printing. I’m surprised I haven’t seen it before. Sorry, I couldn’t be of any help!