Custom kraft paper mailing bags: the six parameters to confirm first.

The first measurement is not the bag, it is the contents. Record the largest outer dimension of the item, its unit weight, and whether it needs its own cushioning space inside the bag or envelope. Inner size then follows from the item plus that allowance.

If the bag is intended for a mixed mail stream rather than one product, measure the largest item you expect to ship and design to that, instead of choosing the size that fits today's average. The available size range is confirmed per order.

Grammage drives stiffness and load-bearing behaviour, so it should be chosen from the item weight, the amount of stacking in transit and the handling the parcel will see — not from a preference for a heavier sheet. Heavier paper costs more and buys stiffness you may not need; lighter paper that creases in transit exposes the contents.

Colour is a separate decision and usually an appearance decision: whether the bag reads as a plain kraft parcel or whether the mailer is part of the brand the customer sees first. Grammage and colour are both discussed per order, and the options available are confirmed in the reply to your inquiry.

This is the parameter most often left until too late. Two structures are used: a single-layer kraft structure for items that already have some rigidity and need limited protection, and a double-layer kraft structure with a honeycomb paper insert between the layers for items that are fragile, likely to be compressed in transit, or travelling through several handling steps.

The difference is visible at the packing bench and in the returns rate, not on the invoice. State the application — what is inside, how heavy, how it travels — and the structure question answers itself. Padded mailer formats built from honeycomb paper layers are described on our mailer page.

Printing has four things to confirm: the artwork file, where it sits on the bag, how many colours it uses, and how those colours register against each other. Each one affects the others — a fine line moves when registration is tight, and a solid block behaves differently from a logo on a kraft surface.

Check the printed result at the sampling stage rather than after a bulk run. A proof on the actual paper is the only reliable way to judge contrast and coverage, and it is far cheaper to correct one sample than a print run.

Closure is an operations decision as much as a packaging one. The points to confirm are whether an adhesive strip is required, where the strip sits relative to the opening, and whether the bag is sealed by hand or fed through sealing equipment. Closure method also affects the structure of the bag and the size of the opening, so it is worth raising in the same inquiry rather than after the artwork is approved.

If a mixed mail stream is being packed on one bench, decide whether one closure type covers everything or whether a second specification is worth carrying.

Water- and moisture-resistant coating can be added by the manufacturing partners, and it is the question buyers ask most often. It is an option rather than a guarantee: coating performance depends on the application, so it has to be confirmed with samples and tests before any moisture-resistance claim is made.

What should not be expected is a waterproof claim, a tested waterproof rating, or a promise that a coated paper bag performs like a plastic one. Where the application genuinely needs that, say so early and it will be handled as a development question rather than a catalogue selection.

Custom configurations are made to order and require sampling and approval before production. The standard size ranges we list are held in stock with no fixed minimum order quantity, and bulk production starts from one hour of bag line output.

Availability, the exact order size, lead time and shipping are confirmed with each inquiry rather than promised on a page, and price is calculated from the specification, structure, quantity, printing, packing, destination and trade term. The more of those you can state up front, the more accurate the quotation is.

A complete brief produces a usable quotation in one round instead of three.

• Inner size, or the packed item with its largest dimension and weight
• Paper grammage and colour, if already decided
• Structure — single-layer kraft, or double-layer kraft with a honeycomb insert
• Printing requirement, with the artwork file and the intended position
• Closure method, and whether sealing is manual or machine-fed
• Quantity for the first order and the expected repeat volume
• Destination port or city, and the trade term you work on

• Paper Cushioning Guide
• Returnable Mailers
• Selection Guide
• Supplier Guide