The Number Line — How Modern Publishers Identify First Printings
The number line — also called the “printer’s key,” “print line,” or “edition line” — is the most common method used by modern publishers to identify which printing a copy belongs to. It appears on the copyright page as a sequence of numbers, and the lowest number present indicates the printing. For most publishers from the 1970s onward, reading the number line is the fastest and most reliable way to determine whether you have a first printing.
How Number Lines Work
The Basic Principle
A typical number line looks like this:
10 9 8 7 6 5 4 3 2 1
The lowest number present indicates the printing. If “1” is present, this is a first printing. For the second printing, the “1” is removed:
10 9 8 7 6 5 4 3 2
For the third printing:
10 9 8 7 6 5 4 3
And so on. This system allows the publisher to update the printing information simply by deleting the lowest number from the printing plate, rather than resetting the entire copyright page.
Variations in Format
Publishers use several variations of the basic number line:
Standard descending: 10 9 8 7 6 5 4 3 2 1
Alternating (split): 1 3 5 7 9 10 8 6 4 2
In the alternating format, the lowest number is still the indicator. If the line reads “1 3 5 7 9 10 8 6 4 2,” the “1” indicates a first printing. For the second printing: “3 5 7 9 10 8 6 4 2” (lowest number is “2”).
With year: Some publishers add year codes to the number line: 02 03 04 05 06 10 9 8 7 6 5 4 3 2 1
This indicates the book was first printed in 2002 (lowest year) and is the first printing (lowest number = 1).
Short lines: Some publishers use shorter lines: 1 2 3 4 5
Same principle — lowest number indicates the printing.
Publisher Variations
While the number line is widespread, its implementation varies by publisher. Not all publishers have used number lines throughout their history, and some combine number lines with other indicators.
Publishers That Use “FIRST EDITION” + Number Line
Many major publishers use both a text statement and a number line:
- Knopf: “FIRST EDITION” statement + number line
- Random House: “FIRST EDITION” statement + number line
- Little, Brown: “FIRST EDITION” statement + number line
- HarperCollins: “FIRST EDITION” statement + number line
For these publishers, the first printing has both the “FIRST EDITION” statement and the “1” in the number line.
Publishers That Use Number Line Only
Some publishers rely on the number line without a separate “FIRST EDITION” statement:
- Penguin Random House imprints (varying practices)
- Simon & Schuster (modern period)
Publishers That Use Text Statements Only
Some publishers, particularly British ones, use text statements without number lines:
- Faber and Faber: “First published in [year]” (no number line, historically)
- Jonathan Cape: “First published [year]” (no number line, historically)
Publishers With Unique Systems
Some publishers have used systems that are not standard number lines:
- Harper & Brothers: Used letter codes (A = first printing)
- Scribner: Used the “A” letter on the copyright page for firsts
Common Pitfalls
The number line alone is not always sufficient. Some publishers have retained the “1” in the number line on printings that are not firsts. Always check for additional indicators.
The “FIRST EDITION” statement may persist. In rare cases, the “FIRST EDITION” text remains on later printings (a publisher’s error). The number line is generally more reliable.
Different imprints, different rules. A publishing house may have different practices for different imprints. Random House’s practices differ from Knopf’s, even though both are part of the same parent company.
Pre-1970s books may not have number lines. Number lines became widespread in the 1970s. Earlier books use text statements, letter codes, or other publisher-specific methods.
Book club editions may copy the number line. In some cases, book club editions reproduce the trade edition’s copyright page, including the number line. Always check for other book club indicators (blind stamp, no jacket price, lighter paper).
How to Read a Number Line: Step by Step
- Find the copyright page (usually the verso of the title page)
- Look for a sequence of numbers, typically at the bottom of the page
- Identify the lowest number in the sequence
- If the lowest number is “1,” the book is a first printing
- Check for additional indicators (“FIRST EDITION” statement, publisher-specific conventions)
- Verify the book is not a book club edition
Historical Context
The number line system was developed as a practical convenience for publishers using offset lithography. In the letterpress era, identifying information was set in movable type and could be changed for each printing. With offset printing from plates, changing any text required making a new plate — expensive and time-consuming. The number line solved this by allowing the publisher to simply scrape off the lowest number from the existing plate, a quick and inexpensive modification.