# What’s the row of numbers on the copyright page of books?

On the copyright page of a book (typically the back of the title page), you'll find a row of numbers. Something like this:

Printed in the United States of America
10   9   8   7   6   5   4   3   2   1

As Dave Taylor explains, the smallest number tells you which printing of the book you have. For example, if you see "10 9 8 7 6 5 4" then you have a fourth printing. Dave doesn't explain why printers use this convention, however.

I forget where I learned this; I think I read it in one of Don Knuth's books. It has to do with how books are historically made. Each page of a book is converted to a metal plate which is used to make impressions. If another printing run is necessary, you load the plates back onto the printing machine and off you go. But how do you indicate that this is a second printing? It would be expensive to burn a brand new plate just to change the word "first" to "second" on the copyright page. Instead, you pre-load all the printing numbers onto your master, and each time you start a new printing run, you scratch off the lowest number.

Even though a lot of book printing nowadays is done with computers rather than metal plates, the old method of indicating a printing is retained out of tradition.

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1. Merit says:

I’ve wondered about this for a long time but its one of those things I never think to look up.

Thanks!

2. Mikkin says:

Errm … I can’t believe you had to explain that.

3. Joe Bruno says:

Often the numbers are odd on one side, even on the other, with 10 in the middle, so that you alternately scrape off the LHS and RHS of the list of numbers. Helps to avoid scraping twice by mistake.

4. richard says:

I was recently browsing through a book and it had the printing number organized differently

1 3 5 7 9 8 6 4 2

Not sure if this was a publisher thing or a new style.

5. Wesha says:

Oh, the long forgotten joy of physical medium. =^.^=

6. grouse says:

It’s unlikely that a single set of metal plates would survive multiple printings. They wear out pretty fast. Instead, this would be used on the film negative used to expose the photosensitive plates. Of course, now people are printing directly to the plates instead, skipping the film step.

7. James says:

Richard: One reason for the odd-even split is that as you rub out more and more numbers, the remainder are still roughly in the middle on the page. If they were simply in order, the 10th printing would have a 10 way over on one side, far away from the other text.

8. Nick Lamb says:

Unintentional hubris or missed by the nitpicker’s corner…

"Even though a lot of book printing nowadays is done with computers rather than metal plates, the old method of indicating a printing is retained out of tradition."

The computer of course doesn’t take the place of the metal plate, any more than it takes the place of the jiffy bag, or of the compressed air cylinder. The industrial printing press is still a dirty, dangerous, noisy machine with ink and metal plates, even though  the typesetting is done with a Mac G4 workstation. The computer controls a machine described (I haven’t seen one) as "a bit like a laser printer" which puts the rasterised image onto photosensitive metal plates ready for the press.

The book nearest to me when I wrote this reads only ’18 20 19 17′ which illustrates that publishers are at once cautious enough to print insufficient copies at first to satisfy the demand, yet optimistic enough to imagine that a further nineteen printings might be sought before they have the opportunity to typeset a new edition incorporating any errata or new material.

Recently though I’ve found that this feature (which I was most impressed by as a child when it was first explained to me) is disappearing in favour of more detailed text listing the date of every printing, or just vanishing altogether even from books which were undoubtedly printed by offset lithography. Similarly the marginal "traffic lights" and crosshairs used for checking the colour registration in daily newspapers are slowly disappearing.

9. Dean Harding says:

missed by the nitpicker’s corner

I don’t think anything is ever "missed" by the "nitpicker’s corner". It’s not like Raymond has a nitpicker’s corner in order to ENCOURAGE this sort of nitpicking… in fact, it’s SUPPOSED to do exactly the opposite — call out just how silly nitpicking actually is. Too bad some people don’t seem to get that.

10. Dominic says:

I thought this method of indicating the printing run was a form of intentional obfuscation.

It’s probably beneficial to the booksellers if there’s no thoroughly obvious way to distinguish between runs/editions. That way, it’s easier to sell old stock when new stock is being sold at the same time (elsewhere, or in the same store).

11. Matt Cramp says:

I believe that once they reach the 11th printing, they use a new line of numbers from 11-20. It’s a convention borne out of tradition, so there’s very little prediction going on there.

For instance, my copy of Harry Potter and the Philosopher’s Stone is a 30-something edition, but the copy I borrowed from the library to read when it first came out stopped at 10. (This was the British version, before the massive bidding war over what became Harry Potter and the Sorcerer’s Stone, and thus it would have been very unusual for the publishers to anticipate a 30-edition print run for a children’s book that couldn’t be sold to any of the major children’s publishers.)

Anyway, I thought all the above was interesting, don’t take it as a nitpick.

12. Norman Diamond says:

I’ve seen something like this in some of the labels attached to the bottom of PCs.  Some vendors have a row of digits (from 0 to B or various other ranges, maybe not always in hexadecimal).  Instead of scratching out a few digits, they actually add a pair of crossout lines, the same way as document revision proposals used to be printed, the same way as Word can display revision histories.  The smallest non-crossed-out digit is the revision level.

By the way, "specs subject to change without notice" means what it says.  A visible notice is a notice, and a version number retrievable from device registers is a visible notice, but the manufacturer can also make changes without providing these kinds of visible notice.

13. Chris Mitchell says:

Our local newspaper still denotes editions printed in a similar manner: 1st edition is two stars, 2nd edition is one star and 3rd edition is none.

14. And what exactly you do with your 12th printing? [Eleventh can be indicated by no number :). Information theory helps.]

15. kbiel says:

Interesting.  I grabbed the top book in the stack on my desk (http://www.amazon.com/dp/0789729970) and looked at its copyright page.  It had this:

06 05 04 03   7 6 5 4 3 2 1

Interpretation of the printing code: The right most double-digit number is the year of the book’s printing; the rightmost single-digit number is the number of the book’s printing.

16. NickN says:

Despite the mention above that metal plates wore out, this numbering was used in hot metal days. Often, especially for rotary plates, a stereotype was cast from the original type, and used for printing and that wore out. When the next edition came, another stereo type was cast after removing the old print run number.

17. Jon says:

A similar system applies for plastic or metal molding. Fancier injection molds have rotatable arrows, but simple molds often have a small grid. A punch is used to create a small dot by the current (and by extension, all previous) months and years. Another dot often indicates the type of plastic used or any changes made to the mold. These markings are usualy found on the inside of plastic objects.

18. magdalena says:

I have a book that shows

03 04 QB 19 18 17 16 15 14 13 12 11 10 9 8 7 6

So it’s the 6th printing, 2003. Does that mean the book I just bought was actually printed in 2003, and sat in a warehouse somewhere until 2007?

Anybody know what the QB represents?

19. Max Lybbert says:

I first saw this explanation in the "Chicago Manual of Style."  However, they talked about using film, and covering the old numbers with some sort of goop.  Same concept though.