As a working rule, 1 mm of greyboard ≈ 600 gsm. A rigid box is built by laminating a wrapping paper onto that board: 1200 gsm (≈2.0 mm) is the standard board for a 100 ml perfume box, and 157 gsm art paper is the most common wrap.
To get outer dimensions from inner, add twice the combined board and paper thickness — there is a wall on each side. Everything you need to calculate it is in section 3.
Greyboard is sold by grammage (gsm) but boxes are designed in millimetres, so you need the conversion. The table below is the working approximation used across the trade.
| Greyboard grammage | Approximate thickness | Common use |
|---|---|---|
| 600 gsm | ≈ 1.0 mm | Lightweight folding cartons, inner partitions, backing board |
| 800 gsm | ≈ 1.3 mm | Small cosmetic cartons, light gift boxes |
| 900 gsm | ≈ 1.5 mm | Slim rigid boxes, secondary packaging, light skincare sets |
| 1200 gsm | ≈ 2.0 mm | The default for perfume, cosmetics and mid-size gift boxes |
| 1500 gsm | ≈ 2.5 mm | Heavier products, premium presentation boxes, book-style boxes |
| 1800 gsm | ≈ 3.0 mm | Large format, heavy sets, boxes that must survive pallet stacking |
Approximate values. Actual thickness varies with board density between mills — always confirm the millimetre figure with your supplier and specify both gsm and mm on the tech pack.
Weight is the primary driver, but the insert matters just as much: a well-designed insert transfers load to the board walls and lets you use thinner board than you would otherwise need.
| Product in the box | Recommended board | Notes |
|---|---|---|
| Under 200 g — lipstick, small skincare, tea | 800–900 gsm | Thinner board keeps the box proportionate; test corner crush before committing |
| 200–500 g — 100 ml perfume, serum sets | 1200 gsm | The industry default for fragrance; enough stacking strength for e-commerce |
| 500 g–1 kg — multi-bottle sets, advent calendars | 1200–1500 gsm | Go to 1500 gsm if the box is shipped as the outer carton |
| 1–2 kg — large gift sets, appliances | 1500–1800 gsm | Consider laminating board to corrugate for very large footprints |
| Over 2 kg or palletised | 1800 gsm + E-flute laminate | Board alone will not survive pallet compression at this size |
You design from the product outwards, so you start with the inner cavity and derive the outer size. Each wall is one board thickness plus one paper thickness, and there are two walls per dimension.
Outer = Inner + 2 × (board thickness + paper thickness)
Worked example — 100 ml perfume box:Two things people forget when they run this calculation:
The wrapping paper is laminated onto the greyboard to give the box its printable surface and its feel. Weight matters less here than you might think — surface and compatibility with your finish matter more.
| Wrapping paper | When to use it |
|---|---|
| 128 gsm art paper | Tight wraps on small boxes with sharp corners; economical at volume |
| 157 gsm art paper | The default for rigid boxes — enough body to hide board grain, laminates cleanly |
| 182 gsm metallic / silver card | Metallic and high-gloss surfaces that need more body; note that non-absorbent coatings need an adhesion check before printing |
| 250–350 gsm specialty | Textured, embossed or coloured papers where the surface character is the design |
| Kraft (recycled look) | Eco positioning; pairs with soy inks and plastic-free structures |
If you are specifying a metallic or heavily coated stock, tell the factory early. Non-absorbent coatings reduce ink adhesion, and the fix — a pre-treatment or a different ink series — has to be planned into the sampling stage, not discovered on the press.
Rigid boxes are largely assembled by hand, which is why tolerances are wider than buyers coming from plastic or metal expect.
Put all four in writing before sampling. Tolerance is one of the first things that quietly widens when a factory is under price pressure, and it is very hard to argue about afterwards.
As a working rule, 1 mm of greyboard is approximately 600 gsm. So 600 gsm is about 1.0 mm, 900 gsm about 1.5 mm, 1200 gsm about 2.0 mm, 1500 gsm about 2.5 mm and 1800 gsm about 3.0 mm. Actual thickness varies with board density between mills, so confirm the millimetre figure with your supplier rather than relying on grammage alone.
1200 gsm, roughly 2.0 mm, is the standard choice. A filled 100 ml glass bottle weighs around 300–400 g, and 1200 gsm gives enough stacking strength for retail and e-commerce transit without making the box look bulky. A slim bottle in a well-designed insert can work on 900 gsm, but confirm with a drop test.
Outer dimension equals inner dimension plus twice the combined thickness of the board and the wrapping paper, because there is a wall on both sides. For a 100 × 100 × 120 mm inner cavity on 1200 gsm board (2.0 mm) with 157 gsm art paper (about 0.18 mm), the outer size is approximately 104.4 × 104.4 × 124.4 mm. Always leave 3–6 mm of clearance between your product and the inner wall.
157 gsm art paper is the most common and economical choice for laminating onto greyboard. 128 gsm is used when you want a tighter wrap on sharp corners, and 182 gsm or heavier is chosen for textured, metallic or specialty papers that need more body to avoid showing the board grain underneath.
Plus or minus 1 mm is the normal working tolerance for hand-made rigid boxes. Print registration tolerance is typically plus or minus 0.15 mm on offset. Specify tolerances in writing before sampling, because tolerance is one of the first things that quietly widens when a factory is under price pressure.
Send your product dimensions and weight. We will come back with a recommended board, paper and insert combination — and the resulting outer dimensions — within 12 working hours.