When you're shipping apparel, soft goods or non-fragile products, a courier bag is the lightest, lowest-cost packaging format available. But many suppliers ask for a dozen specs before they'll even give you a ballpark figure. That isn't how it should work.
At Foldveil, a courier-bag quote starts from three numbers: finished width, finished height and order quantity. Everything else — material, thickness, print, opacity — can be refined after the first conversation. This guide walks through each spec decision, why it matters to cost and performance, and what you can safely defer.
What a courier bag actually is (and when to use one)
A courier bag — also called a poly mailer, shipping bag or mailing sack — is a lightweight polyethylene bag with a self-adhesive closure strip and a protective lip. It is waterproof, tear-resistant, and weighs roughly a tenth of a corrugated box of equivalent capacity.
Use a courier bag when:
- Your product is not fragile (apparel, fabric, soft goods, some accessories)
- You want to minimise dimensional weight and parcel shipping cost
- The bag is the outer layer — the customer sees it first
- You need brand print on the exterior
If your product needs crush protection, pair the courier bag with an inner carton or insert. If the product itself is rigid and needs corner protection, a mailer box or folding carton is the better call. Our mailer selection guide walks through this decision by product category.
The minimum spec that gets you a quote
The three numbers a supplier needs to give you a meaningful price:
| Spec | What to provide | Example |
|---|---|---|
| Finished width (mm) | Internal bag width, laid flat | 350 mm |
| Finished height (mm) | Internal bag height, laid flat | 450 mm |
| Order quantity | Units per order (single or mixed sizes) | 5,000 or 3,000 × 350×450 + 2,000 × 280×380 |
That's it. If you also know the product going inside (apparel, beauty accessories, supplements), the conversation gets faster — it helps the supplier recommend thickness and structure. But neither is required for a first quote.
Why mixed sizes matter. Many custom packaging suppliers enforce a per-size minimum order quantity. At Foldveil, mixed sizes within the same material and print design count toward the same order. If you ship three apparel SKUs in different bag sizes, you don't need three separate production runs.
Material: why mono-PE matters
Most courier bags are polyethylene (PE). The practical difference is whether the bag uses one material family or a laminate of incompatible films.
| Structure | Recyclability | Typical use |
|---|---|---|
| Mono-PE (PE/PE) | Recyclable where PE film collection exists | Standard courier bags, apparel, soft goods |
| PE/EVOH | Recyclable in PE stream (thin EVOH layer tolerated) | Products needing modest oxygen barrier |
| Mixed laminate (e.g., PE/PET) | Not recyclable in standard streams | Legacy structures; being phased out under PPWR |
Foldveil courier bags use mono-PE structures. The recycling story is clean: the bag enters the same PE film recovery stream as grocery sacks and pallet wrap. For a deeper dive on structure trade-offs, see our mono-material mailer comparison.
The compliance note. Whether a specific bag qualifies as "recyclable" in a given market depends on the local collection and sorting infrastructure. Foldveil confirms the applicable disposal claim per factory, material and production run; certificate numbers are shared with the quotation. Do not let a supplier print "100% recyclable" on your bag without evidence of where and how.
Thickness, opacity and closure — the three decisions that follow
Once W×H and quantity are on the table, three specs shape durability and feel.
Thickness (micron or mil). Courier bags typically range from 40 µm (1.6 mil) for lightweight garments to 80 µm (3.1 mil) for heavier or denser products. Higher thickness means more puncture resistance and a more premium hand feel, but also more material weight. The supplier recommends thickness based on your product weight and shipping pattern — you don't need to guess.
Opacity. Three common choices:
| Opacity | Material | Best for |
|---|---|---|
| Opaque (solid colour) | White or grey PE, pigmented | Brand privacy; printed artwork shows clean |
| Semi-opaque | Lightly pigmented PE | Cost-sensitive orders; contents vaguely visible |
| Transparent / clear | Unpigmented PE | Products where the item is the visual (e.g., fabric swatches) |
Closure. The standard is a permanent self-adhesive strip with a tear-off backing paper. Once sealed, the bag is tamper-evident. If you need a secondary seal or resealable strip, mention it early — it changes the bag construction.
Print: what flexo can and can't do
Foldveil courier bags are printed by flexographic (flexo) process. Here's what that means for your artwork:
| Capability | Flexo on PE |
|---|---|
| Max colours | Up to 2 spot colours (confirmed per artwork) |
| Pantone matching | Yes, with tolerance discussion during proof stage |
| Full-bleed | Yes, edge to edge |
| Photographic / gradient | No — flexo is solid-spot; gradients and photos need digital or gravure |
| Single-side print | Standard (exterior face only) |
If your brand requires a four-colour process or photographic print, mention it at the inquiry stage — the production route may differ. But for most DTC apparel and accessory brands, one or two spot colours on a solid white or grey bag is the workhorse spec.
The colour-tolerance conversation. Pantone matching on PE film is not identical to printing on paper. The supplier provides a digital proof showing the expected result; the final production run has a tolerance band. This is standard, not a defect — but it's better discussed before artwork than after delivery.
Sizing: how to pick the right dimensions
The bag should be larger than the product it contains, but not so large that it adds unnecessary dimensional weight or lets the product shift during transit.
Rule of thumb: add 20–30 mm to each dimension of the packed product.
| Product type | Typical bag size (W×H, mm) | Notes |
|---|---|---|
| T-shirt (folded, single) | 250 × 350 | Standard apparel mailer |
| Hoodie / sweatshirt | 350 × 450 | Heavier fabric needs more room |
| Jeans / trousers | 300 × 450 | Folded; may need thicker gauge |
| Towel / blanket | 400 × 550 | Bulky items; check carrier DIM limits |
| Accessories / jewellery pouch | 150 × 220 | Small format; consider tear strip |
If you're unsure, send the supplier your product's folded dimensions and let them recommend the bag size. Most suppliers have standard tooling sizes; matching a close existing size usually costs less than cutting a brand-new die.
Freight reality: courier bags are dimensional-weight products
Courier bags themselves are light. A standard apparel mailer weighs about 10–15 g per unit. But here's the hidden cost: the bags are a volumetric product in freight.
A pallet of 5,000 courier bags might weigh only 60 kg but occupy 1.5 m³. Ocean and air freight carriers charge on the greater of actual weight and dimensional weight (DIM). For courier bags, DIM almost always governs.
What this means for your quote. When you compare supplier prices, make sure you're comparing landed cost — unit price plus freight per unit. A supplier with a 10% higher unit price but 30% better pallet density may be cheaper on the dock. Our packaging cost guide breaks down the components that move the landed price.
PPWR / EPR check: what your bag needs to say
If you ship to EU customers, the Packaging and Packaging Waste Regulation (PPWR) applies from 12 August 2026. For courier bags, the key obligations are:
Recyclability grade. Under PPWR's recyclability-performance grades (A through C, with below-C packaging banned by 2030), mono-PE courier bags are positioned for Grade A or B depending on the collection-and-sorting infrastructure in the target member state. The European Commission is finalising the methodology for assessing recyclability at scale; the implementing act setting out the detailed assessment criteria for performance grades is expected by early 2028 (European Commission, PPWR).
EPR fee modulation. EU member states already charge Extended Producer Responsibility (EPR) fees on packaging. Fees are increasingly modulated by recyclability — meaning a mono-PE bag attracts a lower per-unit fee than a mixed-material laminate. Our EPR fee explainer details how these charges work in practice.
Labelling. PPWR requires harmonised labelling showing material composition and disposal instructions. The exact label format is being finalised; your supplier should provide a label-ready material declaration. The PPWR 2030-targets guide covers the full timeline.
The practical takeaway: if you're ordering courier bags today for the European market, specify mono-PE and ask your supplier how they'll support the labelling requirement.
Quote-ready checklist
Before you send an inquiry, gather what you have:
- Finished bag width and height (mm), or product folded dimensions
- Order quantity (total units, and whether mixed sizes)
- Product going inside (helps thickness recommendation)
- Target market (EU / US / both — drives compliance route)
- Opacity preference (opaque white, grey, or clear)
- Print colours (0–2 spot colours with Pantone references if known)
- Any carrier or marketplace packaging requirements (Amazon SIOC, carrier max dimensions)
What you don't need at first contact: final artwork files, exact Pantone codes, shipping address, or payment terms. Those come after the spec is confirmed and the quote is on the table.
What happens after you send the spec
- Quote within the agreed timeframe. The supplier confirms pricing, MOQ, material structure, and the compliance documents available for this order. Foldveil quotes are made to order; price, MOQ, sample route and lead time are confirmed in the formal quotation.
- Sample route confirmed. Sampling method (digital proof or physical sample), cost and timing are confirmed in the quote — not promised generically beforehand.
- Artwork and proof stage. You provide print artwork; the supplier returns a digital proof showing print placement, colour and dimensions.
- Production and pre-shipment. The supplier confirms the production window with buffer, and provides pre-shipment photos or inspection reports.
Ready to get a quote? Start with your W×H and quantity — a packaging consultant will respond with a spec-confirmation and pricing within one business day.