Choosing Board for Tuck Boxes: White SBS, Kraft and Thickness
What white SBS and kraft board look and feel like, and which thickness to ask for.
By the Tuck Boxes carton desk · Updated
What does gsm tell you about board?
Gsm means grams per square metre. It is the weight of one square metre of the board, so it tells you how much fibre is in the sheet. It does not tell you the thickness directly.
Two boards of the same gsm can feel quite different in the hand. A bulky board made with lighter fibre layers is thicker at the same weight than a dense one. That is why carton makers also talk about calliper.
Our standard board is 350gsm white SBS. Kraft and other stocks can be requested, and your written quote names the board in full.
Paper you print at home is often around 80gsm. Folding carton board is several times heavier, usually somewhere between 250 and 450gsm, which is why it holds a crisp fold.
What is calliper and why does it matter?
Calliper is the thickness of the board, measured in microns. One millimetre is 1,000 microns, so a 450 micron board is 0.45 mm thick. Calliper decides how stiff a panel feels and how much the board adds to each wall.
The figures below are typical ranges seen across the trade. Each mill's board varies, so treat them as guidance rather than a specification.
| Board | Weight | Typical calliper | How it usually feels |
|---|---|---|---|
| White SBS | 300gsm | about 0.38 to 0.43 mm | Light and crisp, good for small cartons |
| White SBS | 350gsm | about 0.43 to 0.50 mm | Firm everyday carton board |
| White SBS | 400gsm | about 0.50 to 0.57 mm | Noticeably stiffer panels |
| Folding boxboard | 300gsm | about 0.45 to 0.50 mm | Bulkier for its weight, cream back |
| Kraft board | 350gsm | about 0.45 to 0.52 mm | Brown, slightly textured surface |
If a supplier quotes only gsm, ask for the calliper too. It is the better guide to how two boards will compare in the hand.
What is white SBS board like?
SBS stands for solid bleached sulphate. The board is white all the way through, not just on the printed face. A cut edge shows white rather than grey or brown, which keeps a carton looking clean.
The coated top side takes full colour print with sharp detail, solid blocks and small text. It also suits foil, spot UV and embossing well. Our foil stamped tuck box designs are all shown on white board.
The uncoated back is smooth and white, so inside printing is possible too.
White SBS is the most common choice for skincare, supplement and electronics cartons. It suits brands that want bright colours, photographs or a clean white background.
How does kraft board look and print?
Kraft board is brown, made from unbleached fibre. It has a natural, slightly textured look that many tea, candle and soap brands like. The brown shows through any ink printed on it.
That changes how artwork behaves. Light colours print darker and duller on kraft than on white, and pale tints can almost vanish. Black and other dark colours read best. See the kraft tuck boxes printed in your artwork for real examples.
Kraft is also a little less smooth than coated white, so very small text and hairlines lose some crispness. Set body text a point or two larger than you would on white board.
- Dark one or two colour designs suit kraft well.
- Fine pale lettering is best avoided or set on a printed white panel.
- Gold and black foil both stand out on brown board.
- Expect the cut edges and inside to be brown as well.
Coated or uncoated: what is the difference?
Most carton boards have a coated printing face. The coating is a thin layer of fine clay and binders that fills the gaps between fibres. Ink sits on top of it, so colours stay sharp and dots do not spread.
Uncoated board absorbs more ink. Colours look softer and fine detail spreads slightly. Some brands like that quieter, papery feel, but it suits bold, simple artwork better than photographs.
The back of a board is often uncoated. That matters only if you want printing inside the carton, where colours may look a little flatter than on the outside.
Which thickness should you ask for?
Thickness is mostly about feel and size. A small carton for a lipstick or a card deck feels right on 300 to 350gsm board. Larger cartons, around 150 mm or more on the long side, often feel better on 350 to 400gsm. Broad panels flex less on heavier board.
Thicker is not always better. Heavy board on a tiny carton makes the tucks stiff and the creases bulky. It also makes the outside size grow, which matters on narrow boxes such as slim lipstick boxes.
If you are unsure, start from our 350gsm white SBS and judge the proof.
Tell us the product, the look you want and any finishes in your brief. We name the board on the written quote. Ask the carton desk about it by phone, WhatsApp or email before you approve.
Why do creases sometimes crack?
Board has a grain, the direction most fibres lie in. A crease folded along the grain is clean. A crease folded across the grain on thick board can show a fine crack in the printed surface.
Cracking shows most on dark solid colours running over a fold. Lamination helps, because the film holds the surface together. Designers also keep the dieline grain direction in mind when laying out panels.
A good crease has a slight bead on the inside of the fold. The cutting forme presses a channel into the board so it bends in a controlled line rather than kinking. Heavier boards need a wider channel to fold cleanly.
Can the inside of the carton be printed?
Yes, on request. Inside printing uses the reverse side of the board. A pattern, a message under the lid or a thank-you line can sit there.
Plan it on the same dieline as the outside. Keep inside artwork clear of the glue flap and its matching strip, just like the outside, so the side seam still bonds.
On kraft board, the inside is brown too, so dark inside print works best. On white SBS, almost any colour shows clearly.
How do you choose board for a new carton?
Here is a simple order of decisions that suits most first orders. It keeps the look, the artwork and the finishes in step with the board.
- Start with the look: clean white or natural brown.
- Check the artwork. Pale colours and fine detail point to white SBS.
- Note the carton size. Long sides over about 150 mm may suit a heavier board.
- Think about finishes. Foil, spot UV and soft touch all show best on coated white.
- Ask for the board in writing on the quote, by name and gsm.
- Check the proof, which shows the dieline drawn for that board.
Board thickness changes the dieline slightly. Our guide on how to measure a tuck box explains how it affects outside sizes.
What about board for windows and inserts?
Windows cut from heavier board leave a cleaner edge. The frame around the window still needs 5 to 8 mm of board to stay flat. Inserts are often cut from the carton's own board, so the colours match.
A rise-up insert on a dropper or perfume carton is usually the same weight as the outer box. Our window tuck boxes with die-cut fronts show how the frame sits on white board.
Film behind a window is glued to the inside of the panel. On kraft board, the brown frame around the film gives a natural border that many candle and tea brands use.
