Materials & Board · In-depth guide
Packaging materials guide: board, paper and corrugated
Published Reviewed
Almost every packaging decision comes back to one question: what is the box made from? For most UK brands the answer is one of three board families: folding boxboard for printed cartons, corrugated board for boxes that travel, and greyboard for rigid presentation boxes. This guide explains each material, how to compare them and how to decide, so you can brief a specification rather than guess at one.
The board determines how the packaging feels in the hand, how well it protects the product, how the print reproduces, which finishes can be applied, and how much it costs to make and ship. Every Custom Boxez box is made to the dimensions of the product it holds rather than to a stock size, so material selection is part of the specification, not a fixed catalogue choice. As a packaging supplier rather than a print shop, we specify the board, the construction and the finish together.
The three board families
Nearly all printed packaging is built from one of three material families. Getting this choice right first makes every later decision simpler, because it settles how the box is constructed, how it ships and which finishes are open to you.
| Family | What it is | Typical thickness | Typical use | Key strength |
|---|---|---|---|---|
| Folding boxboard (FBB) and solid bleached board (SBS) | A single-ply sheet, printed, cut and creased flat, then folded and glued | Typically 250–400 gsm, roughly 0.3–0.65 mm | Retail cartons, cosmetics, supplements, food cartons, sleeves | Print quality and shelf presentation |
| Corrugated board | A fluted paper layer glued between flat liners | About 1.5 mm (E flute) to 6–7 mm (double wall) | Mailer boxes, transit boxes, counter displays, inserts | Strength, cushioning and transit protection |
| Greyboard (rigid board) | Thick, dense board wrapped in printed or speciality paper | Typically 1.5–3 mm | Gift and presentation boxes, premium retail, jewellery, drinks | Perceived value and structural permanence |
Thickness figures are typical ranges. They vary by mill and corrugator, and your quotation confirms the exact board.
Which family should you choose?
Choose folding boxboard when the box sits on a shelf and print quality matters most. Choose corrugated when the box has to survive a courier network or carry weight. Choose rigid when the box itself is part of the product experience and is likely to be kept. If you are weighing two of these against each other, our comparisons of rigid boxes and folding cartons and mailer boxes and folding cartons go through the trade-offs in detail.
Folding boxboard and SBS
Folding boxboard is a layered virgin-fibre board with a bulky core, which makes it stiff for its weight. SBS is bleached pulp all the way through, so its creases and cut edges stay bright white and it gives the finest print. Both are made to be printed, creased and folded, and both ship flat and are folded up at packing. Our folding boxboard and SBS page covers grades, backs and calliper in full.
Recycled carton board, often called white-lined chipboard, is the third option in this family. It has a white printing face over a grey recycled core and needs more weight to reach the same stiffness. We compare it with virgin board in recycled vs virgin fibre.
Corrugated board
Corrugated board works like a beam: flat liners resist bending while the wavy fluting between them holds the liners apart and absorbs impact. It is graded by flute size, by liner type and weight, and by the number of walls. It is the material for mailer boxes, transit boxes, counter display units and fitted inserts. The corrugated board page explains liners, grades and strength tests.
Greyboard for rigid boxes
Greyboard is never printed directly. It is cut into panels, joined at the corners, wrapped in a printed or speciality paper and lined inside, so the board carries the structure and the wrap carries the look. Rigid boxes arrive assembled and keep their shape for years of reuse, which is why they suit gifting and premium retail. See greyboard for thicknesses, density and corner construction.
Kraft and speciality papers
Kraft is not a separate family but a fibre and colour choice that runs across all three. There are kraft carton boards, kraft corrugated liners and kraft wrapping papers for rigid boxes, all with the natural brown look and long, strong fibres of unbleached kraft pulp. Kraft board explains how it prints and which finishes suit it.
Speciality papers are the textured, metallic, coloured and leatherette-style wraps used mostly over greyboard. The colour or texture is in the paper itself, so the box can be finished with a foil logo or a deboss and little or no print. See speciality papers.
Material by product: a quick reference
The table below shows where each board usually ends up. Treat it as a starting point: the product's weight, how it travels and the look you want can move the recommendation either way.
| Product or situation | Usual material | Why |
|---|---|---|
| Cosmetic or skincare carton | SBS or FBB, typically 300–350 gsm | Bright white face, fine print, clean creases |
| Supplement or health carton | FBB, typically 300–350 gsm | Firm panels around tubs and bottles at a sensible weight |
| Printed e-commerce mailer | E flute, or B flute for heavier contents | Ships the order and presents it on opening |
| Heavy transit box or glass bottles | B flute, C flute or double wall, often with dividers | Stacking strength and cushioning |
| Gift or presentation box | Greyboard, commonly 2 mm, wrapped | A keepsake box that holds its shape |
| Jewellery box | Greyboard, typically 1.5–2 mm | Small, precise and firm-fitting |
| Spirits or wine gift box | Greyboard, typically 2.5–3 mm, with a fitted insert | Carries weight without flexing |
| Tea, coffee or candles with a natural look | Kraft carton or kraft-wrapped rigid box | Natural finish that suits bold, simple artwork |
| Counter display unit | E or B flute corrugated | Holds its shape on the counter and takes full-colour print |
| Inserts and dividers | Carton board or corrugated; foam where genuinely needed | Holds the product in place and does much of the protective work |
For most folding cartons the construction matters as much as the board. A crash lock bottom lets a heavier carton carry weight through its base, while a roll-end tuck front is the classic corrugated mailer construction.
Understanding GSM and board thickness
GSM means grams per square metre: the weight of one square metre of board. It is the most common way to describe carton board, and within one type of board it tracks stiffness closely. A higher-GSM board feels more substantial and holds its shape better.
Thickness is a separate measurement, called calliper, and in the UK it is quoted in microns (µm); 1,000 microns is 1 mm. GSM and calliper are linked by density, so two boards of the same GSM can be different thicknesses. A 300 gsm FBB is noticeably thicker than a 300 gsm SBS, because its core is bulkier. When you compare quotations from different suppliers, check whether they are quoting weight or thickness, and which board type.
North American suppliers describe calliper in points, an imperial unit. Convert before you compare: our guide to GSM, microns and points shows how, with a conversion table.
| Material | How it is usually specified | Typical range |
|---|---|---|
| Carton board (FBB, SBS, recycled) | GSM, with calliper in microns | 250–400 gsm; about 300–650 µm depending on board type |
| Corrugated board | Flute letter plus liner type and weight | E, B, C flute or double wall; liners commonly 115–200 gsm |
| Greyboard | Thickness in millimetres, with weight or density | 1.5–3 mm |
| Wrap and speciality papers | GSM | Commonly 100–170 gsm |
Does a higher GSM always mean a better box?
No. Beyond the point where the carton holds its shape and protects the product, extra board weight adds cost and shipping weight without adding useful performance. The right specification is the lightest board that does the job well, which is why the product's dimensions and weight drive the recommendation rather than a default figure.
Corrugated flute grades
Corrugated board is classified by its flute, the wave-shaped inner layer that provides cushioning and stacking strength. The flute is chosen for the weight and fragility of the contents and for how the box must print.
| Flute | Typical thickness | Best suited to | Print surface |
|---|---|---|---|
| E flute | About 1.5 mm | Lighter contents where the printed finish matters most | Smoothest; takes detailed print well |
| B flute | About 3 mm | General-purpose postal and transit boxes | Good; slight ribbing possible with direct print |
| C flute | About 4 mm | Heavier or bulkier products needing more cushioning | Fair; ribbing more likely |
| EB double wall | About 4–5 mm | Double-wall strength with a better print face | Good on the E flute side |
| BC double wall | About 6–7 mm | Heavy, fragile or stacked loads, floor displays | Coarse; usually printed via a laminated sheet |
There is a genuine trade-off here: the finer the flute, the better the print surface but the less cushioning it provides. Heavier flutes protect better but reproduce fine artwork less crisply. For most branded e-commerce mailers, E flute is the usual starting point and B flute the step up for heavier contents. Our E vs B vs C flute comparison goes further into strength, folding and internal space.
Liner and surface options
The surface of the board decides how the print looks and which finishes will work. These are the main options you will see on a specification.
- White surface. A bleached, coated white face gives a clean printing surface and is necessary for accurate full-colour and photographic artwork. On corrugated this is a white-top liner or a printed white sheet laminated to the flute.
- Kraft (brown) surface. Unbleached board with a natural appearance. It takes one- and two-colour print well and is widely used for tea, coffee, candles, food to go and artisan packaging.
- Coated or uncoated face. Most carton board has a mineral coating on its printing face for smoothness and sharp print. Uncoated board has a softer, more natural feel and more absorbent surface. We compare them in coated vs uncoated board.
- Barrier-coated board. A board with a grease- or moisture-resistant layer, specified where food sits directly against the board or the product is oily or damp. The grade and coating must be chosen for that use; see our food packaging guide.
Can you print full colour on kraft board?
You can print CMYK on kraft, but the brown base shifts the colours. White cannot be printed with ordinary process inks, and pale shades read warmer and darker than the artwork suggests. Where exact colour matching matters, a white-top kraft or white board is the reliable choice. Where a natural look is wanted, one or two dark Pantone colours on kraft usually give a better result than full colour, and a gold, copper or white foil adds a crisp highlight.
Virgin and recycled fibre
Carton board, liners and greyboard can each be made from virgin fibre, recycled fibre or a mix. Virgin fibre gives brighter surfaces and more stiffness for the weight; recycled fibre reuses material already in circulation but is usually denser, greyer inside and less stiff per gram, so it may need a heavier grade for the same job.
Neither is automatically the better choice. Many boxes combine both: a recycled test liner inside a corrugated board with a kraft liner outside, for example, or a recycled greyboard core wrapped in a virgin-fibre printed paper. Our recycled vs virgin fibre guide compares performance, appearance and where each is used.
Printing methods
We print CMYK, Pantone (PMS) spot colours or a combination, or supply boxes unprinted.
- CMYK builds colours from four process inks. It is the right choice for photographic images and artwork with many colours or gradients.
- Pantone (PMS) uses pre-mixed inks matched to a numbered reference. It is the right choice for flat brand colours that must reproduce consistently across a product range and across reprints.
- CMYK plus Pantone is common on premium cartons: process colours for imagery, with one or two spot colours for the logo and brand panels.
- No printing means plain board, used where the packaging is functional or is branded with an applied label or a stamp.
Our CMYK vs Pantone guide explains when to use each. The print process matters too. Litho gives the finest quality and suits longer runs; digital printing needs no plates and suits short runs and several versions; direct flexographic print is common on corrugated transit boxes. See litho vs digital printing for how the choice affects quality and unit cost.
Printing inside the box is also possible on most constructions, from the inner liner of a mailer to the liner paper of a rigid box. It works best when the inside surface is white or coated; see printing inside boxes.
Finishing options
Finishing is applied after printing and changes how the box looks, feels and wears. The finish you want can influence the board, so it belongs in the specification from the start rather than being added at the end.
| Finish | What it does | Works best on | Detail |
|---|---|---|---|
| Matt, gloss or soft-touch lamination | A thin clear film that protects the print and sets the surface | Coated carton board, printed mailer sheets, rigid-box wraps | Lamination |
| Aqueous or UV coating | A liquid coating applied on the press, lighter than film | Coated carton board | Lamination |
| Spot UV | Gloss varnish on selected areas for contrast | Matt or soft-touch laminated surfaces | Spot UV |
| Foil blocking | Metallic or coloured foil on logos and type | Laminated board, kraft, speciality papers | Foil blocking |
| Embossing and debossing | Raises or presses in a design | Rigid-box wraps, uncoated and speciality papers, carton board at moderate depth | Embossing and debossing |
| Window patching | A clear film over a die-cut opening | Folding cartons and sleeves | Window patching |
Lamination protects print from scuffs in transit and handling, and Free Lamination is standard on every order. Matt reads as restrained, gloss lifts colour saturation, and soft-touch gives a velvety feel. Other finishes are priced by coverage and process, so a full-coverage finish and a small spot UV logo are very different line items. If you are building a premium box, our overview of luxury packaging finishes shows which combinations work on which materials.
Construction and included options
Every custom box needs tooling and conversion, and these are included in a Custom Boxez specification. No Die Charges are standard on every order.
- Die cutting. Cutting the flat blank to shape with a cutting forme made for your dimensions.
- Creasing (scoring). Pressing a line into the board so it folds cleanly and squarely.
- Gluing. Bonding the seams of a folded carton or mailer, or the wrap and liner of a rigid box.
- Perforation. A line of small cuts that lets a section tear away, used for tear strips and display packaging.
Inserts are specified alongside the box. Die-cut carton board and corrugated inserts are usually the most economical way to hold a product in place, and they keep the whole pack paper-based. Moulded pulp and foam are alternatives for heavier or more fragile products. See custom inserts.
Environmental considerations
Recyclable and lower-impact material options are available. Because recyclability depends on the specific board, coating and finish chosen, the right options are confirmed with your quotation rather than assumed across the whole range. Some finishes, laminates in particular, affect how a carton is processed at end of life. If recyclability or recycled content is a priority for your brand, raise it at specification stage, where it can influence the material choice, rather than after the artwork has been approved.
Anything you print on the box about its materials must be accurate. Our sustainable packaging guide and recyclable packaging materials explain the options and the points to check.
How material choice affects your quotation
Material is one of the biggest drivers of cost, but it rarely works alone. These are the factors that move a quotation, and our guide to what determines packaging cost explains each in more depth.
- Dimensions. Board is cut from sheets, so larger boxes use more material and fewer fit on each sheet.
- Board and coating. Heavier boards, SBS, double wall and specialist coatings cost more than plain carton board or single wall.
- Quantity. Set-up is spread across the run, so the unit cost falls as quantity rises. Custom orders start from 50 boxes.
- Printing. One- or two-colour print is the baseline; full CMYK, extra spot colours and inside printing add to the cost.
- Finishing. Priced by process and coverage, beyond the Free Lamination that is standard on every order.
- Construction. Rigid boxes involve hand assembly and ship assembled, so they cost more to make and move than flat-packed cartons.
- Inserts. Carton board and corrugated inserts are usually the most economical; foam and complex fitments cost more.
Timing is part of the same conversation. Speciality papers can take longer to source than standard board, and rigid boxes take longer to make than folding cartons. Tell us your required delivery date and our team will confirm whether the timing is achievable. Delivery is included on every order; your quotation confirms the delivery address and timing.
Choosing your material in five questions
Work through these in order. Those five answers determine the board, and they are exactly what we ask when you request a quotation.
- What is the product and what does it weigh? Size and weight set the minimum board strength and the likely thickness.
- Does the box ship, sit on a shelf, or both? A courier journey points to corrugated or an outer shipper; a shelf points to carton board or rigid.
- Does anything touch food directly? Direct contact narrows the choice of board and coating; wrapped products leave it open.
- How must the artwork reproduce? Photographs and exact brand colours need a white, coated surface; bold logos work on kraft.
- What finish does the brand call for? Soft-touch, foil, emboss and spot UV each favour particular surfaces.
If you are unsure of any answer, tell us what you know. Our packaging specification guide shows how to write a brief that gets a like-for-like quotation.
Common mistakes
These are the material mistakes we see most often, and each is easy to avoid at specification stage.
- Choosing by GSM alone. GSM without the board type says little; a 300 gsm FBB and a 300 gsm recycled board behave very differently.
- Comparing quotations in different units. One supplier quoting points, another GSM and a third a flute letter are not comparable until converted. See comparing packaging quotes.
- Over-specifying the board. Double wall for a light product adds weight, bulk and cost without adding useful protection.
- Under-specifying for the journey. A carton that looks perfect on a shelf will not survive a courier network on its own; it needs a mailer or an outer shipper.
- Full-colour photographs on natural kraft. The brown base darkens and warms every colour; use white-top kraft or white board if the imagery must be accurate.
- Measuring the box instead of the product. Board thickness and inserts change the internal space; give us the product's own measurements.
- Leaving recyclability or food contact until last. Both can change the board and the finish, so raise them before the artwork is approved.
- Sending a rigid box through the post without protection. A rigid box is a presentation box, not a transit carton; plan an outer shipper or a collapsible design.