A book wrap mailer is a single corrugated blank that folds around a flat product and seals with a self-adhesive strip. Sizing it is not the same as sizing a box, because the depth is not one number. It is a range, set by where the creases fall. Work through these five steps in order.
Step 1: measure the flat footprint
Lay the product flat and measure length and width at the widest points, including any shrink wrap, belly band or card backing that ships with it. If you sell a range of titles or SKUs, measure the largest. One die covering the whole range is almost always better than several dies covering each SKU, and the die is included either way.
If you are packing printed product, these published trim sizes are a reasonable sanity check on your own measurement: US mass market paperback near 4.25 x 6.87 in, US trade paperback 5.5 x 8.5 in, US hardcover 6 x 9 in, US letter 8.5 x 11 in, ISO A4 210 x 297 mm. Treat them as industry-typical anchors, then measure your actual product.
Step 2: add clearance, but not much
A book wrap works because it is snug. Too much clearance and the product slides inside the wrap, which defeats the whole style. Add just enough that the product goes in without forcing and the wrap still holds it. This is one of the few formats where a tight fit is the goal rather than a risk.
Step 3: define a thickness range, not a thickness
The parallel creases along each side wall are what make the style flexible. A mailer creased for a range will fold down onto a thin item and out for a thicker one. So the number you give a supplier should be a minimum and a maximum thickness, for example the thinnest and thickest titles you will ever mail in it. If you only give one figure, you get a mailer that fits one product and wastes material on everything else.
Step 4: choose the board
| Board | Approximate caliper (industry-typical) | Where it fits a book wrap |
|---|---|---|
| E flute | about 1/16 in (1.6 mm) | Thin, light items, best print surface, folds tightest |
| B flute | about 1/8 in (3.2 mm) | The common all-round choice, good crush resistance for a mailer |
| C flute | about 5/32 in (4 mm) | Heavier or thicker loads, stiffer wrap, slightly bulkier folded |
Remember that the board caliper is consumed by every fold. A wrap that folds four times around a thick item uses more depth than the arithmetic of the product alone suggests.
Step 5: settle the seal and the print
Decide whether you need one adhesive strip or a second for returns, because that changes the flap length and therefore the blank. Decide whether the print is a one colour brand mark or full coverage, since that changes price more than board usually does. Then ask for the dieline.
What it costs and how long it takes
Minimum order is 100 boxes. Price starts from about $0.48 per unit at bulk volumes and is confirmed on your written quote. The cutting die, the plates, design support, US shipping and a digital proof before anything prints are included. Production runs from West Chicago in the US and Guangzhou in China in three lanes: rush (expedited production plus air freight, a premium of about 7 to 25% depending on the job), standard (air) and cost saver (sea), from about 7 business days, plus 2 to 5 for delivery.
If you would rather work from your scenario than from a method, what size book wrap mailer do I need takes the shortcut route. For a glued alternative that holds a fixed depth, see book boxes or mailer boxes. Send your largest footprint and your thinnest and thickest products through the quote form and ask for the crease range to be drawn to cover both.
