Flexible packaging · Formats
Bag Types & Formats — Find the Right Structure for Your Product
Bag format is a functional decision before it is a visual one. The structure you choose sets your filling speed, shelf presence, reclosability, freight efficiency — and a large share of your unit cost. This page compares the six formats we manufacture, with the applications each one suits and the materials each converts best from. Every format is custom-sized, printed up to 10 colours, and available with 30–100% certified PCR content where the material allows.
Bag type 01
Flat Bags
The simplest structure in flexible packaging: two webs sealed on three sides, open at the top. That simplicity is the point — flat bags are the lowest-cost format per unit, run fastest on high-speed filling lines, and pack densest in cartons and freight.
Where flat bags win
Industrial liners and component bags, bakery and produce overwrap, garment inner bags, and any high-volume application where the pack is opened once and discarded. They are also the standard base for printed promotional packaging where cost per impression matters. See industrial packaging.
Material fit
Converts cleanly from recycled PE (the default, at 50–80 µm), recycled PP for a stiffer garment bag, and PLA where a compostable claim is required. Oxygen-sensitive goods should move up to a multi-layer coex flat bag or vacuum pouch.
Specification notes: No gusset means limited fill volume relative to footprint — flat bags suit flat or granular products, not bulky ones. Seal quality on the bottom seal is the critical defect mode; we run seal-strength checks as standard QC. Custom sizes within our 800–1300 mm slitting range, MOQ from 500 pcs, sampling in 3–5 days.
Bag type 02
Stand-Up Pouches
A bottom gusset lets the filled pouch stand unsupported on a shelf — which is why stand-up pouches dominate retail food, pet food, coffee and snack categories. The standing billboard effect replaces secondary packaging and gives you front-and-back print area that flat formats cannot match.
Where stand-up pouches win
Any product sold from a shelf rather than a rail or a parcel. Coffee and tea, dried fruit and nuts, snacks, powdered products, and premium gift food. Optional windows combine shelf visibility with barrier film performance. See food packaging.
Material fit
Kraft paper laminates are the classic natural-look choice; multi-layer coex for oxygen-sensitive or vacuum-adjacent products; PLA for compostable retail lines (good stiffness suits the format); clear or metallised laminates for maximum product visibility. Bottom-gusset forming works best within defined stiffness ranges — we validate material-to-format compatibility before quoting.
Specification notes: Fill volume depends on gusset depth, not just pouch width — send us your fill weight and product bulk density and we will size the pouch correctly the first time. Add a press-to-close zipper (see Zipper Bags) for multi-serve products. Sampling 3–5 days on standard lines.
Bag type 03
Zipper Bags
Press-to-close zippers add reclosability — the single feature that most extends a pack's useful life after opening. Zipper closures can be applied to flat bags, stand-up pouches and shaped formats, so treat this as a feature family as much as a bag type.
Where zipper bags win
Multi-serve food (snacks, cereals, frozen fruit, grated cheese), pet treats, hardware and components the user accesses repeatedly, and any product where staleness or spillage after opening drives complaints. For e-commerce, zipper closures also reduce returns caused by spillage in transit when used as inner packs.
Material fit
Multi-layer coex where the contents need oxygen or aroma barrier after repeated opening; rPE for dry goods and non-food; kraft laminates for premium dry food. The zipper flange must seal to the film's sealant layer — a compatibility check we run as standard.
Specification notes: Zippers add cost and slightly slow filling lines; for single-serve products they are wasted spend and we will say so. Zipper track options (standard, wide, child-resistant-adjacent designs) are selected against product and market. MOQ from 500 pcs; engineer reply within one working day on structure questions.
Bag type 04
Self-Seal Bags
A self-seal bag closes with a pre-applied adhesive strip — peel, fold, press. No heat sealer, no zipper track, no equipment. This is the format behind e-commerce mailers, and the reason: fulfilment operations close thousands of bags per shift by hand.
Where self-seal bags win
Courier and mailer bags above all — our recycled PE mailers with 30–100% PCR ship into UK and EU e-commerce programmes at scale; see e-commerce mailers. Also document sleeves, garment bags for apparel fulfilment, and sample or parts bags in industrial kitting. Tamper-evident strip options show clear evidence of opening for high-value or regulated goods.
Specification notes: For double-use mailers (customer returns), a second adhesive strip can be applied — a low-cost feature that materially improves return-logistics experience. Custom print up to 10 colours turns the mailer into the first brand touchpoint. Sampling 3–5 days; MOQ from 500 pcs.
Bag type 05
Shaped Bags
Shaped bags are die-cut to a custom outline — bottle silhouettes, character shapes, rounded-corner pouches, spouted formats. The shape itself becomes the brand asset: on a shelf of rectangles, a distinctive outline is what stops the eye.
Where shaped bags win
Promotional and campaign packaging, licensed-character products, gift and seasonal ranges, single-serve samples and sachets where the outline carries the brand, and spouted pouches for liquids, purees and sauces. Spouted formats in multi-layer coex handle hot-fill to ~90 °C within our standard range. See gift packaging.
Material fit
Coex and laminated films die-cut cleanly and hold barrier at the seal edge; kraft laminates for premium gift shapes; PLA for compostable promotional formats. Very intricate outlines stress the seal at tight corners — our engineers will adjust the die-line to keep seal width safe.
Specification notes: Die tooling is a one-time cost amortised across the run; unit economics favour shaped bags from mid-volume upward. Die-line review is part of our free pre-production process, and sampling (3–5 days on standard lines) confirms the shape on your actual filling equipment before the full run.
Bag type 06
Carrier Bags
The handled retail bag — patch, die-cut or soft-loop handles — remains the highest-frequency brand touchpoint in physical retail. Every customer carries your print out of the store.
Where carrier bags win
Fashion and apparel retail, grocery and convenience, pharmacy, event and exhibition merchandising, and any programme where the bag itself is part of the brand experience. Heavy-gauge versions serve garden centres, hardware and bottled goods. See shopping bag programmes.
Material fit
rPE at 50–80 µm with 30–100% PCR is the volume standard — GRS-certified content (TE-00057717) that supports EU PPWR and UK packaging reporting, at roughly 2.6 t CO₂e avoided per tonne of virgin PE replaced (industry estimate). Kraft laminates for premium and gift retail; PLA for compostable carrier programmes where collection infrastructure exists. Handle style and reinforcement are matched to target load weight.
Specification notes: Load rating is engineered through gauge and handle patch design, not guesswork — tell us the target carry weight and we size accordingly. We already supply carrier and shopping bag programmes into UK supermarket and European retail supply chains (clients anonymised under NDA). MOQ from 500 pcs; volume pricing at 5,000 / 20,000 / 100,000 pcs.
Quick comparison
Bag Type × Material × Application — Quick Comparison
| Bag type | Best-fit materials | Typical applications | Cost tier | Key trade-off |
| Flat bag | rPE, rPP, PLA, coex | Industrial liners, garment inners, overwrap | Lowest | No shelf presence; limited volume |
| Stand-up pouch | Kraft laminate, coex, PLA | Retail food, coffee, snacks, pet food | Medium | Gusset sizing must match bulk density |
| Zipper bag | Coex, rPE, kraft laminate | Multi-serve food, components, pet treats | Medium | Zipper adds cost & slows filling |
| Self-seal bag | rPE (mailers), rPP | E-commerce mailers, apparel fulfilment, documents | Low–medium | Adhesive must match transit climate |
| Shaped bag | Coex, laminate, kraft, PLA | Promotional, gift, spouted liquids, samples | Higher (die tooling) | Corner seal integrity needs die-line review |
| Carrier bag | rPE, kraft laminate, PLA | Retail, grocery, events, heavy-gauge | Low–medium | Load rating engineered by gauge + handle |
Typical positioning — final specs confirmed against your product and filling line.
Buyer questions
Frequently Asked Questions
Self-seal rPE mailers in almost all cases — adhesive closure for pack-line speed, 50–80 µm puncture resistance, 30–100% PCR content for PPWR and UK plastic-tax reporting. For apparel, add a second adhesive strip for customer returns. We supply this format into UK supermarket and European e-commerce programmes.
Yes — and consolidating on one film family simplifies certification and inventory. rPE converts into flat, self-seal and carrier bags; kraft laminate covers stand-up, zipper and shaped formats. Tell us your product range and we will propose the minimum set of materials that covers all formats.
Four things: product (weight and bulk density), filling method (manual or line speed), target market (compliance reporting), and annual volume estimate. An engineer replies within one working day with a format recommendation, typical-value spec and pricing at 5,000 / 20,000 / 100,000 pcs tiers. MOQ from 500 pcs; sampling free on standard lines, 3–5 days.
Get started
Get a Quote on Any Bag Type
Send product, filling method, target market and volume — an engineer replies within 1 working day with a format recommendation and typical-value spec.
Certification package (GRS TE-00057717 · OEKO-TEX SH003 168118 · SMETA ZC5000065444) within 24 hours of enquiry.