Reference
Packaging glossary
The packaging terms and specs buyers ask about most, explained in plain English — so you can order the right thing with confidence.
- Compostable packaging also: Compostable packaging materials, Certified compostable
- Packaging certified to break down into compost under defined conditions. Standards such as EN 13432 cover industrial composting; home-compostable items are certified separately.
- Corrugated cardboard also: Corrugated board, Corrugated fibreboard, Cardboard
- A material made of one or more fluted paper layers glued between flat liners. The air-filled flutes make it light, strong and the standard for shipping boxes.
- Die-cut boxes also: Die cut boxes, Mailer boxes, Roll-end boxes
- Boxes cut and creased from board using a shaped die, producing a precise flat blank that folds into shape without tape, glue or extra assembly.
- Direct thermal labels also: DT labels, Thermal labels, Ribbonless labels
- Labels printed by heating chemically coated paper directly, needing no ink or ribbon. Ideal for short-life uses like shipping labels, but the print fades over time.
- Double-wall cardboard also: Double wall board, Twin-wall corrugated
- Corrugated board with two fluted layers and three liners, giving extra strength and cushioning. It is used for heavy, fragile or stacked shipments and moving boxes.
- Food-safe packaging also: Food-contact packaging, Food grade packaging
- Packaging made from materials approved for direct contact with food, so nothing harmful transfers into it. In the UK this is governed by food-contact materials regulations.
- gsm (grams per square metre) also: Grammage, g/m2, Paper weight
- The weight of paper or board expressed as grams per square metre. Higher gsm generally means a thicker, stiffer, more durable material.
- Gummed paper tape also: Water-activated tape, WAT, Gum tape, Kraft paper tape
- A kraft paper tape with a starch adhesive activated by water. It bonds into the box surface for a strong, tamper-evident, fully recyclable seal.
- Kraft paper also: Brown paper, Kraft wrapping paper
- A strong, tear-resistant paper made by the kraft pulping process, usually brown. It is widely used for wrapping, void fill, mailers and paper tape.
- Low-noise tape also: Quiet tape, Low-noise packaging tape, Silent tape
- Packing tape engineered to unwind quietly rather than with a loud screech, making it more comfortable for busy or high-volume packing areas.
- Mailing bags also: Mailer bags, Poly mailers, Postal bags, Courier bags
- Lightweight bags, in plastic or paper, with a self-seal strip for posting non-fragile items. They are light and slim, which helps keep postage down.
- Micron also: Micrometre, um, mu
- A unit of thickness equal to one thousandth of a millimetre, used to measure plastic films such as pallet wrap and mailing bags. Higher micron means a thicker, tougher film.
- Pallet wrap also: Stretch wrap, Pallet stretch film
- Stretchable plastic film wound around a loaded pallet to bind items together and stabilise the load for transport and storage.
- PiP (Pricing in Proportion) also: Pricing in Proportion, PiP format, Royal Mail size-based pricing
- Royal Mail's Pricing in Proportion system, where postage is set by an item's size and thickness as well as its weight. It sorts mail into format bands such as Letter, Large Letter and Small Parcel.
- Recyclable packaging also: Recyclable materials, Kerbside recyclable packaging
- Packaging that can be collected, reprocessed and made into new products. Recyclability depends on the material and on whether local facilities actually accept it.
- Royal Mail Large Letter also: Large Letter format, LL
- A Royal Mail PiP format for flat items up to 353 x 250 x 25mm and 750g. Staying within these limits keeps postage cheaper than Small Parcel rates.
- Single-wall cardboard also: Single wall board, Single-wall corrugated
- Corrugated board made from one fluted layer sandwiched between two flat liners. It is the everyday choice for lightweight postal boxes and cartons.
- Stretch film also: Stretch wrap, Pallet stretch film
- A highly stretchable plastic film that clings to itself to bundle and secure loads. Applied under tension, it is used mainly to stabilise palletised goods.
- Thermal transfer labels also: TT labels, Ribbon labels
- Labels printed by melting ink from a ribbon onto the label surface. The result is a durable, long-lasting image suited to product, asset and long-storage labelling.
- Void fill also: Packing filler, Box filler, Dunnage
- Material used to fill empty space in a box so contents cannot move in transit. Common types include paper, air pillows, bubble wrap and loose fill.
Questions these terms come up in
What packaging do I need for ecommerce orders?
A box or mailing bag sized to the product, void fill or bubble wrap so nothing moves, plus tape and a courier label. Right-sizing keeps postage and damage down.
Which boxes fit Royal Mail Large Letter?
Boxes within 353 × 250 × 25mm post as a Large Letter. Our PiP postal boxes are cut to sit inside those limits so you pay the cheaper rate.
What is the best void fill for fragile items?
Pair cushioning (bubble wrap) around the item with void fill (kraft paper or air cushions) to stop movement. Fill any gap larger than about 3cm.
Poly or paper mailing bags — which should I use?
Poly mailers are waterproof, lightest and cheapest; paper mailers are kerbside recyclable with a premium feel but less water resistance.
Not sure which spec you need?
Tell us what you're packing and how you ship. We'll recommend the right size, grade and material — and price it for your quantity.
