A book wrap mailer has no single standard size. It is specified as an internal length and width, plus a depth range that the scores fold down to. Get the internal footprint from the item you are shipping and the wrap does the rest, which is why a trim size chart is the useful starting point and a box size chart is not.
Start from the trim size, not from a box
Publishing trim sizes are standardised in a way box sizes are not, so they are a sound place to begin. These are industry-typical trims, not iBox stock sizes, and you should still measure the copy in your hand because covers overhang the page block.
| Format | Industry-typical trim | Note |
|---|---|---|
| Mass market paperback | 4.25 x 6.87 in | Smallest common US trim |
| Digest paperback | 5.5 x 8.5 in | Exactly half a US letter sheet |
| US trade paperback | 6 x 9 in | The most common trade trim |
| Royal hardcover | 156 x 234 mm (about 6.14 x 9.21 in) | Case boards sit proud of the block |
| A5 | 148 x 210 mm | ISO, common outside the US |
| A4 | 210 x 297 mm | Manuals, catalogues, art books |
Where the depth comes from
A book wrap is a flat blank with several parallel score lines running across the side walls. You fold up to whichever score matches the stack in front of you, so one blank covers a range of depths rather than a single one. That is the whole point of the style: a bookseller shipping one paperback today and four tomorrow uses the same mailer. When you specify one, give the maximum depth you expect to ship, not the average, because folding down is free and folding up is impossible.
How to measure for one
- Measure the item at its widest point, including the cover overhang, any dust jacket and any shrink wrap.
- Stack the largest shipment you realistically send and measure that stack, not one copy.
- Add clearance for whatever goes in with it: a packing slip, a card, a thin foam sheet.
- Write the result as internal length x width x depth, in that order.
- Say on the quote that the figures are internal. Outside dimensions differ by roughly two board thicknesses per axis, and that gap is where most sizing mistakes live.
Board and print
Book wraps are normally made in a fine single wall board so the scores fold cleanly and the pack stays light for postal rates. A coarser flute stiffens the panel but resists the fold and prints less sharply. If you are weighing the two common options, our note on E flute against B flute covers what each does to caliper and print surface. Kraft liners print warm and muted, white top liners hold colour closer to a screen, and either can take a one-colour logo without changing the structure.
Ordering, minimums and turnaround
Minimum order is 100 boxes. Unit pricing starts from about $0.48 per unit at bulk volumes and is confirmed on your written quote. The cutting die, the printing plates, design support, US shipping and a digital proof are all included, which is the reason a genuinely custom internal size is worth specifying: there is no tooling penalty for fitting your book exactly. Production runs in three lanes, rush (expedited production with air freight), standard (air) and cost saver (sea), from about 7 business days, plus 2 to 5 for delivery. Specialty imported items can run up to about 12 weeks. We make book wraps at two plants, West Chicago in the US and Guangzhou in China.
If you already have the trim size and the largest stack you ship, that is everything a quote needs. Send those two numbers through the quote form and we will come back with the internal dimension we would cut, or walk the measuring method with you first on how to size a book wrap mailer.
