What are PDF page labels?
Page labels give PDF pages numbers like i, ii, iii or A-1 that match the printed page. PDF by Zaweba sets them for ranges of pages in Pages > Page labels.
Page labels are the page numbers a PDF shows you, as opposed to the plain count of pages from the start of the file. They let the front of a book be numbered i, ii, iii, an appendix A-1, A-2, and the main text 1, 2, 3, so the number on screen matches the number printed on the page. In PDF by Zaweba you set them in Pages > Page labels.
Without labels, every PDF is numbered 1, 2, 3 from the cover onwards. That's fine for a short letter, but in a book with twelve pages of front matter, page 1 of the text is page 13 of the file, and telling someone to "go to page 40" sends them to the wrong place.
Why they matter
Labels close the gap between the file and the printed page. A reader who sees page 40 printed at the foot of a page can type 40 into the page box and land on it, instead of guessing an offset. In a report that cites page numbers, in a legal bundle, or in course notes where the lecturer says "turn to page 12", that small match saves a lot of confusion.
They also make the app's own displays clearer. In PDF by Zaweba, the labels appear in the page box, in the status bar and under the thumbnails, so as you scroll you always see the number the document itself uses.
How to set them
Open Pages > Page labels. Choose a range of pages and give it a numbering style, such as lower-case Roman numerals for the front matter. Then choose the next range, such as the main text, and give it ordinary numbers starting from 1. An appendix can have its own range with a style like A-1.
Work from the start of the document to the end, one range at a time. When you are done, scroll through and watch the page box and thumbnails; the numbers should match what is printed on each page.
Getting the ranges right
Check the printed numbers first. Flick through the document and note where the numbering changes: the cover, the front matter, the first page of the main text, any appendices. Those are your ranges.
Remember the cover. Many books don't print a number on the cover or title page at all, but they still count. Give them their own range so the main text starts at the right number.
Labels change what you see, not the page order. Setting labels doesn't move, add or remove pages; it only renames them. If pages are in the wrong order, fix that first.
Labels and other tools
Bookmarks make good use of labels. When you add a bookmark with Ctrl+B without selecting any text, it's named after the page label, so a quick outline of a long document picks up the right numbers.
Labels also help when you send a document for review. A colleague who comments "see page iv" means the same page you see, not the fourth page of the file.
Printing is the one place to stay alert. When you type a page range into the Print window, such as 1-3, 7, 10-, look at the preview to be sure the pages you get are the ones you meant, because a label and a page's position in the file can differ.
Page labels are a small piece of the PDF format that does a useful job, and PDF by Zaweba makes them a matter of a few ranges in one window.
