Materials · Carton board
Folding boxboard (FBB) and SBS board
Folding boxboard (FBB) and solid bleached board (SBS) are the two virgin-fibre boards behind most printed folding cartons. Both are made to be printed, creased and folded, usually between 250 and 400 gsm. FBB is stiffer for its weight; SBS is white all the way through and gives the cleanest print, creases and edges. This page sets them side by side, with calliper, coated and uncoated backs, so you can choose with confidence.
Overview
How FBB and SBS are made, and why it matters
Folding boxboard is built in layers. The top is bleached chemical pulp with a mineral coating for print; the middle is mechanical pulp, which is bulky and gives stiffness without much weight; the back is a thin bleached layer that is often cream or manila rather than bright white. The European grading calls cream-backed FBB GC2 and white-backed FBB GC1, and you will see those codes on board specifications.
Solid bleached board, usually called SBS (solid bleached sulphate) or SBB, is made from bleached chemical pulp through its whole thickness. It is bright white on the face, the back and the cut edge, so creases and exposed edges stay white. It is also denser than FBB, which means an SBS carton needs slightly more weight to reach the same stiffness.
Weight is quoted in GSM, grams per square metre. Thickness, called calliper, is quoted in microns (µm): 1,000 microns is 1 mm. The two are linked by density, so a 300 gsm FBB is usually around 430–480 microns thick, while a 300 gsm SBS is usually around 370–420 microns. US suppliers quote calliper in points, an imperial unit; in the UK we specify GSM and microns, and any quotation you compare should do the same.
Both boards are coated on the printed face. The back is where they differ most. A coated back, sometimes sold as coated two sides, prints almost as well as the face, which matters if you want artwork inside the carton. An uncoated back is more absorbent, so inside print looks softer and dark colours look flatter, but it glues well and is the more economical choice.
Most cartons we make fall between 250 and 400 gsm. Lighter weights suit small cartons, sleeves and inserts; 300–350 gsm is the everyday range for cosmetic, supplement and food cartons; 350–400 gsm adds stiffness for larger panels, heavier contents and crash lock bottoms that carry weight. Tell us the product and its weight and we will recommend the grade on your quotation.
Specification
Typical specification
| Specification | Typical range | Notes |
|---|---|---|
| FBB, cream back (GC2) | 250–400 gsm | The everyday folding carton board: stiff for its weight, with a bright coated face and a cream or manila back. |
| FBB, white back (GC1) | 250–400 gsm | As GC2 but with a whiter back, for cartons that are seen open or lightly printed inside. |
| SBS, uncoated back | 250–400 gsm | Bright white through the sheet with clean white creases and edges, and premium print on the face. |
| SBS, coated back | 250–400 gsm | Coated on both sides for full-quality print inside and out; the premium carton option. |
| Calliper guide at 300 gsm | FBB about 430–480 µm; SBS about 370–420 µm | Indicative figures only. Every mill publishes its own data, and your quotation confirms the exact board. |
Best for
Where it works best
Cosmetics and skincare cartons
SBS for bright white and clean edges; FBB where stiffness per gram matters more.
Supplement and health cartons
300–350 gsm FBB gives firm panels around tubs, bottles and blister packs.
Food cartons for wrapped products
Virgin-fibre boards are the usual choice for dry and pre-wrapped food; direct contact needs a suitable grade and coating.
Sleeves and belly bands
250–300 gsm prints well and wraps neatly around a tray or a rigid box.
Tuck end and crash lock cartons
The standard boards for straight tuck, reverse tuck, snap lock and crash lock constructions.
Card inserts and dividers
Die-cut board holds products in place inside cartons and mailer boxes.
Cartons printed inside
Coated-back SBS gives inside artwork the same quality as the outside.
Limitations
Where it falls short
- Carton board protects presentation, not heavy impacts. For posting, use a mailer box or put cartons in an outer shipper.
- Dark solid colours across a crease can show fine white cracking on any coated board; lamination and correct creasing reduce it.
- The mechanical-pulp core of FBB can yellow slightly with long exposure to daylight, most visibly on the back and edges.
- An uncoated back gives softer, flatter inside print; choose a coated back if inside artwork matters to you.
- Towards 400 gsm, board is harder to fold neatly on very small cartons; large or heavy products may be better in corrugated or rigid board.
- SBS needs more weight than FBB for the same stiffness, so it earns its place when white edges or print quality justify it.
Pairs with
Works well with
Finish
Lamination
Free Lamination protects print and reduces cracking along creases.
Read moreFinish
Spot UV
Laminated FBB and SBS give spot UV a smooth base and strong contrast.
Read moreFinish
Foil blocking
Smooth coated board takes fine foil detail cleanly.
Read moreFinish
Window patching
Carton board is the usual base for cartons with a clear window.
Read moreBox style
Crash lock bottom boxes
Heavier carton board gives a crash lock base the strength to carry weight.
Read moreProduct
Folding cartons
Our printed folding cartons are made in FBB or SBS.
Read more
Compare
FBB and SBS side by side
| Feature | Folding boxboard (FBB) | Solid bleached board (SBS) |
|---|---|---|
| Construction | Layered: bleached outer plies, mechanical-pulp core | Bleached chemical pulp throughout |
| Printed face | Coated white, very good print | Coated bright white, the finest print |
| Back | Cream (GC2) or white (GC1), usually uncoated | White; uncoated or coated |
| Cut edges and creases | Show a slightly creamy core | White all the way through |
| Stiffness for its weight | Higher, thanks to the bulky core | Lower, because the sheet is denser |
| Typical calliper at 300 gsm | About 430–480 µm | About 370–420 µm |
| Colour over time | Can yellow slightly in long daylight exposure | Stays white for longer |
| Best for | Most retail, food and supplement cartons | Cosmetics, fragrance and premium cartons |
How to choose
How to choose between FBB and SBS
Choose FBB for most cartons
Pick FBB when the carton needs to be stiff and light, the inside is not a feature, and a creamy cut edge is acceptable. It covers most retail, food and supplement cartons.
Choose SBS for white edges and fine print
Pick SBS when creases and edges must stay white, the artwork is detailed or photographic, or the carton sits in a cosmetics, fragrance or premium range.
Match the back to the inside
If you print inside, or the carton is opened on camera or on the counter, specify a white or coated back. If nobody sees the inside, an uncoated back is fine.
Let size and weight set the GSM
Small cartons fold best at 250–300 gsm; tall, wide or heavy products usually need 350–400 gsm. Tell us the product weight and we will recommend the grade.
Ask about recycled carton board
Recycled grades such as white-lined chipboard (GD2) are grey inside and less stiff for their weight. They can suit simple cartons; ask us whether one fits your product.
Finished work
Folding boxboard and SBS on finished packaging
Straight Tuck End Boxes · Folding boxboard and SBS
Folding boxboard and SBS questions
Questions buyers ask
Anything not covered here, put it in the notes on your quote and we will answer it directly.
Ask on your quoteWhat is folding boxboard (FBB)?
Folding boxboard is a layered virgin-fibre carton board with a bulky mechanical-pulp core between bleached outer layers and a coated printing face. It is stiff for its weight and prints well, which makes it the everyday board for printed folding cartons.
What is SBS board?
SBS stands for solid bleached sulphate, also called SBB (solid bleached board). It is made from bleached chemical pulp through its full thickness, so it is white on both sides and at the cut edge, with a very smooth surface for fine print.
What is the difference between FBB and SBS?
FBB has a mechanical-pulp core, so it is stiffer for its weight but shows a creamy edge. SBS is bleached chemical pulp throughout, so it is whiter, smoother and cleaner at the creases, but denser. FBB suits most cartons; SBS suits premium and cosmetic cartons.
What GSM should my folding carton be?
Most cartons are 250–400 gsm. Small, light products suit 250–300 gsm; the everyday range for cosmetics, supplements and food is 300–350 gsm; larger or heavier products usually need 350–400 gsm. We recommend the grade from your product size and weight.
What is the difference between GSM and microns?
GSM is weight: grams per square metre of board. Microns measure thickness, or calliper: 1,000 microns is 1 mm. Two boards of the same GSM can differ in thickness because of density, which is why FBB is thicker than SBS at the same weight.
Do I need a coated back or an uncoated back?
Choose a coated back if you print inside the carton and want that print to match the outside. An uncoated back is absorbent, so inside print looks softer, but it glues well and is the more economical choice when the inside is plain or rarely seen.
What do GC1 and GC2 mean?
They are European grades of folding boxboard. GC1 has a white back and GC2 has a cream or manila back; both have a coated white printing face. Recycled carton board has its own grades, such as GD2 for a grey back.
Can FBB or SBS be used for food packaging?
Both are widely used for food cartons. Where food touches the board directly, the grade and any barrier coating must be chosen for that use, and you remain responsible for your own compliance. Tell us the food and how it is wrapped and we will specify accordingly.
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