Sizing a poly mailer is not the same problem as sizing a box. A mailer is a flat sleeve that has to wrap a three dimensional item, so the thickness of what you are shipping eats into the width, and the closure eats into the length. Work through it in that order and the first sample fits.
The method, step by step
- Pack the item as it will ship. Fold the garment, bag the item, add the tissue and the card. Measure the finished pack, not the bare product.
- Measure the flat footprint. Width across, length top to bottom, with the pack lying flat and slightly compressed under your hand.
- Add for thickness. The film has to travel around the pack, not just across it. Add roughly half the pack thickness to each side of the width. A one inch thick pack needs about an inch of extra width in total.
- Add a seal allowance. Leave about 2 in of length above the contents for the flap and the adhesive strip. Contents pressed up against the seal is the classic cause of a mailer popping open in the network.
- Test before you print. Pack a real order into a plain mailer at the calculated size and put it through a day of normal handling.
The sizes the industry already uses
Poly mailer dimensions have settled into a small set of flat sizes across the industry. They are worth knowing because they give you a comparison point and because your fulfilment team may already stock one. They are not our stock sizes, and a custom printed run can be any size you like.
| Common flat size | Typically used for |
|---|---|
| About 6 x 9 in | Accessories, single small garments, documents that need a waterproof wrap |
| About 9 x 12 in | A folded t-shirt, soft goods, small apparel orders |
| About 10 x 13 in | The general apparel workhorse, one to two garments |
| About 14.5 x 19 in | Bulkier apparel, multiple items, a folded jacket |
| About 19 x 24 in | Large or multi item orders, bedding, oversized soft goods |
What a poly mailer will not do
Film protects against water and abrasion. It does nothing about crushing or impact. Anything rigid, fragile, or with a corner that can tear through, belongs in a box or in a padded mailer rather than a plain poly one. Printed matter that must arrive flat needs a stiffener. If you are shipping a mix of soft and rigid items, split the order rather than sizing one huge mailer that arrives creased.
Print, thickness and the gauge conversation
Film thickness is quoted in mil, and thicker film costs more and tears less. Heavier contents and longer transit distances both argue for a heavier gauge. Print behaves differently on film than on board: solid coverage looks strong, fine type and photographic detail do not hold as well as on paper, and a white film base gives more accurate colour than a coloured or metallic one. Design with a bold logo, clear return address block and a simple palette.
Ordering
Custom printed mailers start at a minimum of 100 units. Pricing runs from about $0.48 per unit at bulk volumes and is confirmed on your written quote, with design support, US shipping and a digital proof included before anything prints. Turnaround is quoted per job in three lanes, rush (expedited production plus air freight), standard (air) and cost saver (sea), from about 7 business days, plus 2 to 5 for delivery. If you are ordering a season's worth in one go, the cost saver lane is usually the cheapest way to buy them.
Send your packed measurements to the quote form and we will come back with a flat size and a gauge. If you are still deciding between formats, read what size poly mailer do I need or compare against custom mailer boxes.
