Printing sits on top of the same polyethylene bag a plain mailer uses, so the postage math never sees it.
A folded hoodie in a 12 × 15 in mailer, quoted 2026-08-19
We described a folded hoodie in a custom printed 12 × 15 in poly mailer to the SMKlog calculator, weighed at 1.2 lb, Berkeley Heights, NJ 07922 to Chicago, IL 60601. Every figure below is exactly what came back.
| Carrier | Service | Price | Estimated transit |
|---|---|---|---|
| USPS | Ground Advantage | $11.17 | 4-5 business days |
| UPS | Ground Saver | $11.22 | 4 business days |
| UPS | Ground | $11.57 | 4-5 business days |
| USPS | Priority Mail | $15.05 | 4-5 business days |
| UPS | 3 Day Select | $16.37 | 4-5 business days |
Nothing about the word “custom printed” in the product description changed a single rate. The calculator sizes and weighs the parcel exactly as it would a plain mailer; our poly mailer test against a box ran the same kind of bag with a different garment and a different lane, and it is worth reading side by side to see how weight and lane move the number rather than the printing.
Sizing a custom mailer to what you sell
One hoodie or heavy layer
12 × 15 in is the size we tested and it fits one folded hoodie or sweatshirt with room to seal properly. Go a size up rather than force the seam.
A few folded t-shirts
10 × 13 in covers two to three folded tees. Stacking more than that turns a flat mailer into a lumpy one, and lumps are what tear a poly seam in transit.
Multi-item or bundled orders
Past a few garments, a 14 × 19 in or larger mailer or a small box holds the load without the bag ballooning past its own dimensional headroom.
Where the printing actually comes from
SMKlog buys shipping labels; it does not print or sell packaging. Sellers who want their own logo on a mailer are choosing between two kinds of supplier, and the choice mostly comes down to order size.
Print-on-demand packaging sites
Several online printers take custom poly mailer orders starting in the dozens rather than the thousands, with a design proof before anything ships. The per-bag price is highest at this end and falls as the order grows.
Bulk packaging suppliers
Wholesale packaging companies print larger custom runs for a lower per-bag cost, but the minimum order is correspondingly bigger, closer to a case than a handful.
Plain bags, if branding can wait
A plain mailer with a printed thank-you card or a sticker gets most of the unboxing effect without committing to a print run before you know your volume. Our guide to sourcing plain poly mailers covers where those come from.
Custom clothing shipping bags, answered
What is the difference between a custom poly mailer and a plain one?
Printing. A custom mailer is the same 2-mil to 2.5-mil polyethylene film as a plain one, run through a printer first so it carries a logo, a color, or a design instead of a blank white or gray surface. Neither the film nor the seal changes.
Does a custom-printed bag cost more to ship?
No. Carriers price by weight and package dimensions, not by what is printed on the outside. Our own hoodie test quoted the same $11.17 to $16.37 range a plain bag of the same size and weight would have returned on 2026-08-19.
What size bag fits a folded hoodie or a few t-shirts?
A 12 x 15 in mailer holds one folded hoodie or two to three folded t-shirts. Two or three shirts alone fit a smaller 10 x 13 bag. Go up a size before you go up a shipping tier: an overstuffed mailer risks a seam split more than it risks dimensional weight.
Where do small clothing sellers get custom mailer bags printed?
Print-on-demand packaging companies sell single-color and full-color custom poly mailers with order minimums as low as a few dozen bags, priced per unit and dropping as the order grows. Bulk packaging suppliers print larger custom runs more cheaply per bag but ask for a bigger minimum order. Neither route is something SMKlog sells or fulfills.
Is a poly mailer secure enough for clothing sales?
For folded, non-fragile garments, yes, provided it is fully sealed along the adhesive strip and the corners. It will not stop a determined thief at a porch, and it offers no cushioning, so anything with buttons, embellishments, or a rigid hanger clip is safer boxed.