How to Read a Number Line to Identify First Editions
The number line — also called the printer’s key, impression line, or print line — is the row of numbers on the copyright page that identifies which printing of a book you are holding. It is the single most common method used by publishers since the mid-twentieth century to indicate printing history, and understanding how to read it is the most fundamental skill in first edition identification.
How the Number Line Works
The basic principle is simple: the lowest number present in the line indicates the printing. For a first printing, the number 1 must be present.
Standard Format
A typical number line looks like this:
1 3 5 7 9 10 8 6 4 2This indicates a first printing. The number 1 is present.
For the second printing, the publisher removes the 1:
3 5 7 9 10 8 6 4 2This indicates a second printing. The lowest number is 2.
For the third printing:
3 5 7 9 10 8 6 4The lowest number is 3, indicating a third printing.
Why the Numbers Alternate
The numbers often run from low to high and then back down (1 3 5 7 9 10 8 6 4 2) or in some other non-sequential arrangement. This is a practical matter: the number is set in metal type or pre-printed on a printing plate, and the printer removes the lowest number from one end of the line for each new printing. The alternating arrangement makes it easy to remove numbers from either end while keeping the remaining numbers visually centred.
Variations by Publisher
While the basic principle is universal, publishers vary in their specific formatting:
Random House and Imprints (Knopf, Vintage, Crown, etc.)
Random House and its imprints use a standard number line. First printings show:
First Edition
2 4 6 8 9 7 5 3 1Both the “First Edition” statement AND the number 1 in the line indicate a first printing. For subsequent printings, “First Edition” is removed and the number line is updated.
Simon & Schuster
Typically uses a number line with the lowest number indicating the printing:
1 3 5 7 9 10 8 6 4 2HarperCollins
Uses “FIRST EDITION” on the copyright page along with a number line. The number 1 must be present for a true first printing.
Penguin Random House (post-merger)
The merger of Penguin and Random House consolidated many imprints, but each generally maintained its pre-merger identification practices. Always check the specific imprint.
Little, Brown
Uses a number line. Some editions include “First Edition” text; others rely solely on the number line.
Houghton Mifflin Harcourt
Uses a number line, sometimes with the year of publication indicated by a second row of numbers:
1 2 3 4 5 6 7 8 9 10
13 12 11 10 09 08 07 06The first row shows the printing; the second row shows the year. This example indicates a first printing from 2006.
W.W. Norton
Typically uses a standard number line.
Publishers Without Number Lines
Before the Number Line Era (Pre-1970)
Many publishers did not adopt number lines until the 1970s or later. Earlier identification methods include:
“First Edition” or “First Printing” statement — some publishers simply stated “First Edition” on the copyright page and removed the statement for subsequent printings.
“First Published [year]” without additional printing information — common in British publishing. If the copyright page says “First Published 1954” and nothing else, it is likely a first printing. If it says “First Published 1954 / Reprinted 1955, 1957, 1960,” it is a later printing.
The “A” on the copyright page — Scribner’s used an “A” on the copyright page to indicate a first printing (1929 onward). The “A” was removed for subsequent printings.
No explicit indication — some publishers, particularly before 1950, provided no clear first-edition identification. Identifying first printings requires publisher-specific knowledge, reference to bibliographies, and comparison with known first printings.
British Publishers
British publishers have historically been less consistent than American publishers in indicating printings. Many use the “First Published” statement without a number line. Some key practices:
Faber and Faber — “First published in [year] by Faber and Faber” indicates a first printing. Subsequent printings add “Reprinted” dates.
Jonathan Cape — “First Published [year]” on the copyright page. Later printings add “Reprinted” or “Second Impression” statements.
Penguin Books — uses “First published [year]” for the first Penguin edition, with subsequent printings listed.
Common Pitfalls
”First Edition” Does Not Always Mean First Printing
Some publishers print “First Edition” on the copyright page of every printing in the first edition — including the second, fifth, and tenth printings. The number line, not the “First Edition” text, is the definitive indicator. If the text says “First Edition” but the number line starts with 3, it is a third printing.
Paperback Number Lines
Many books are published simultaneously in hardcover and paperback. Each format has its own number line and printing history. A first printing of the paperback is not the same as a first printing of the hardcover (unless the paperback is a PBO — paperback original).
Reissues and New Editions
A “First [Publisher] Edition” or “First [Imprint] Edition” may indicate that this is the first time the book has been published by this particular publisher — but it is not the first edition of the text. A “First Vintage Books Edition” of a novel originally published by Knopf is a paperback reprint, not a first edition.
Missing Number Lines
If the number line has been physically removed (cut, whited out, or obscured), investigate why. Dishonest sellers occasionally alter copyright pages to disguise later printings as first printings.
Quick Reference
To determine if a post-1970 book is a first printing:
- Turn to the copyright page
- Find the number line (usually near the bottom of the page)
- Look for the number 1 — if present, it is a first printing
- Check for any “First Edition” or “First Printing” text as confirmation
- If no number line is present, look for edition statements and consult a publisher-specific reference
For pre-1970 books, consult Bill McBride’s A Pocket Guide to the Identification of First Editions or Zempel and Verkler’s First Editions: A Guide to Identification for publisher-specific practices.