Coated (C2S), One-Side-Coated (C1S) and Grey Board: The Difference

When a customer asks "how much is the box", the answer is largely set by the paper used. The paper grade directly affects both the price and how the print will look. There are actually many paper grades; this article focuses on the three most common basics in the industry: coated paper, one-side-coated board and grey board. What each is for, how it behaves in print and what sets its price, in order.

What exactly are coated paper, C1S board and grey board?

Coated paper is coated on both sides with a filler such as kaolin. It is called coated two sides, or C2S for short. Because both sides are coated, both are suitable for printing, and it is the surface that renders colours most vividly. It comes in a range of grammages; depending on the request it can be wrapped onto a body or, at grammages like 300-350 gsm, used on its own.

One-side-coated board is coated on a single side. Internationally it is known as coated one side, or C1S; in Turkey it is called "bristol". Both sides of C1S can be printed; the difference is quality. The coated side gives vivid, clean print, while the uncoated side is rougher and prints more matte and less vivid. On C2S both sides are coated, so both print with the same vividness. It also comes in a wide grammage range; for paper bags, for example, 200, 230 and 250 gsm are common.

Grey board is a completely different product. Grey on both sides, it is a thick, cheap material usually made from recycled fibre. It is never shown on its own; its job is to carry. Glued and laminated in layers it becomes solid-board products, and the body of rigid boxes is mostly this. Papers like testliner and fluting come from the same recycled-fibre family: fluted and combined they form corrugated board, laminated flat they form solid board.

Why does print quality depend on the paper?

The same design looks different on different papers. On a coated surface (coated paper, and the coated side of C1S) ink stays on the surface instead of soaking into the pulp; colours are saturated and details are sharp. Coated paper also comes in matte and gloss: gloss makes colour look more vivid, matte gives a reflection-free, calmer texture.

On uncoated papers the surface is open; some ink is absorbed and print comes out more matte and less vivid. That is a separate topic; here we focus on coated papers.

Grey board is not printed on directly, especially not by offset. Printing with techniques like screen printing or flexo is possible, but if you want a vivid, clean result grey board is not printed directly; its visible face is the coated or special paper wrapped over it. We cover the cost impact of the printing method in the printing methods and cost article.

What is chromo board, and how does it differ from grey board?

What most people in Turkey picture when they say "karton" (board) is usually chromo board. Chromo board is white on one side and grey on the other. Its white side is printable; its grey side, like grey board, cannot be printed. This is where it differs from C1S: both sides of C1S can be printed (at different quality), whereas chromo's grey side cannot. So a single product carries both a carrier body and a printable face, which is why it is very common in folding cartons. Duplex board follows a similar logic: white on one side, grey on the back.

Chromo board is generally cheaper per kilo than C1S board; it is easier and faster to produce. The cheapest is grey board, while coated paper sits at the most expensive end. But these are per-kilo (per-tonne) rankings, and because their uses are entirely different, saying outright "which is cheaper" can be misleading.

What sets the price: grammage or the per-tonne price?

Both. Paper is sold by the tonne; each grade has a per-tonne price. Grammage translates that per-tonne price into a sheet: the heavier the sheet, that is the higher the grammage, the higher the cost per sheet. In a folding box, material cost is the product of three variables:

So "is 150 gsm coated paper or 400 gsm grey board more expensive" has no single answer. Per tonne, coated paper is always more expensive than grey board. But per sheet, because of its high grammage, 400 gsm grey board can come out dearer than 150 gsm coated paper. The market's current prices decide it.

Quick comparison

The silent cost of choosing the wrong paper

Grammage higher than needed is a silent loss. Making a box that would work at 400 gsm at 500 gsm means paying a quarter more material on every order. The reverse is also true: paper too thin to hold up means crushed product and returns. The right approach is not to pick the cheapest paper but to find the lowest safe grammage and the right grade the product actually needs.

If you also need the flute and strength side, the corrugated board types article helps. To see paper choice on a concrete box, carton box cost calculation shows it step by step. To try how the price moves when you change grammage and paper, you can use the packaging cost calculator.