Coated Paper: What it is and how it changes your design

 

Coated paper is paper with a mineral layer, usually clay or calcium carbonate, applied to its surface and then polished. The coating fills the gaps between fibers, so ink sits on top instead of soaking in. The result is sharper images and brighter color than uncoated paper. It also changes how you should prepare your design file.

Most articles on this topic stop at "coated is shiny, uncoated is natural." This one uses published data from paper mills and the ISO printing standard to show what actually differs, and which settings in your file depend on the paper you pick.

 

What the coating does

The coating reduces how much ink the paper absorbs. Printers call this ink holdout. Because the ink stays on the surface, dots keep their shape, colors stay saturated, and fine detail holds.

Coated does not mean glossy. A coated sheet can have a gloss, silk (also called satin) or matte finish. All three have the coating. The finish comes from how much the surface is polished afterwards.

You will also see two labels on paper specs:

• C2S (coated two sides): coating on both faces. Standard for flyers, brochures and magazines.
• C1S (coated one side): coating on the front only. Used for postcards, labels and packaging where the back needs to take a pen, glue or a stamp.

 

Gloss, silk and matte: the measured differences

Sappi publishes technical datasheets for its Magno range, one of the most common coated papers in European print shops. The three finishes differ in shine and in thickness, even at the same weight.

Gloss, measured with the TAPPI 75° method (higher means shinier):

• Magno Gloss: 64 to 68%
• Magno Satin: 38%
• Magno Matt: 15 to 22%

Thickness at 300 gsm:

• Magno Gloss: 228 µm
• Magno Satin: 282 µm
• Magno Matt: 309 µm

So a 300 gsm matte sheet is about 35% thicker than a 300 gsm gloss sheet from the same mill. Gloss paper is calendered (pressed) harder to get its shine, which compresses it. If you want a business card that feels thick, the finish matters as much as the gsm number. Our paper weight guide covers this in more detail.

 

Coated vs uncoated paper

Coated paper:

• Sharper images and more saturated color, because ink stays on the surface
• Thinner at the same gsm (Magno Gloss 300 gsm is 228 µm; Munken Pure, a common uncoated design paper, is 339 µm at 300 gsm)
• Resists dirt and moisture better
• Hard to write on with a pen, and ink from ballpoints or stamps can smear
• Dark solid areas on matte and silk can scuff unless varnished or laminated

Uncoated paper:

• Softer, less saturated color, because ink spreads into the fibers
• Easy to write on, which is why letterheads, envelopes and forms are almost always uncoated
• Thicker and more tactile at the same gsm
• Works well for embossing, letterpress and foil, where texture adds to the effect

 

How coated paper changes your design file

This is where the choice of paper stops being a printer's detail and becomes a design decision. Four things in your file depend on it.

1. The color profile

When a file is converted to CMYK, it is converted for a specific printing condition. In Europe, the current standard profiles from the European Color Initiative (ECI) are:

• PSO Coated v3 (FOGRA51) for coated paper
• PSO Uncoated v3 (FOGRA52) for uncoated white paper

PSO Coated v3 replaced ISO Coated v2 (FOGRA39), which many templates still use. In the US, the common coated reference is GRACoL 2013.

Converting with the wrong profile does not break the file, but the colors on paper will not match what you approved on screen. If your printer names a profile, use that one. If they do not, ask.

2. Dot gain

Halftone dots grow when they hit paper. The ISO 12647-2:2013 offset standard sets the expected growth, called tone value increase, at the 50% tint:

• Coated paper (FOGRA51): 16%, so a 50% tint prints at roughly 66%
• Uncoated paper (FOGRA52): 22%, so a 50% tint prints at roughly 72%

The profile compensates for this during conversion, which is another reason to use the right one. In design terms: light tints, soft gradients and shadow detail survive better on coated paper. If you have a pale 10% background tint or a photo with dark detail, coated stock is the safer choice.

3. Pantone spot colors

Pantone publishes separate guides for coated (C) and uncoated (U) paper because the same color looks different depending on how the paper takes the ink. On uncoated stock, the ink soaks in and the color prints noticeably duller. Pick your brand color from the guide that matches the paper you will print on. If you use both stocks, check the color on both.

4. Ink limit and rich black

Every profile has a total ink limit: the maximum sum of C, M, Y and K in any area. PSO Coated v3 and PSO Uncoated v3 both set it at 300%. The older ISO Coated v2 allowed 330%.

For large black areas on coated paper, use a rich black such as 60C 40M 40Y 100K (240% total). It prints deeper than 100K alone and stays under the limit. Keep small text in 100K only, because four-color black text blurs if the plates are slightly misaligned.

 

Finishing: folding, varnish and writing

Heavier coated paper can crack along a fold as the coating breaks. Sappi's datasheets recommend pre-creasing (scoring) from a thickness of 135 µm. For their papers, that threshold lands at:

• Magno Gloss: from 200 gsm (150 µm)
• Magno Satin: from 170 gsm (141 µm)
• Magno Matt: from 150 gsm (150 µm)

The same weight needs scoring on one finish and not on another. If your design has a fold and a dark color runs across it, the crack will show as a white line. Ask for scoring, or keep solids away from the fold.

Matte and silk coated papers show scuff marks on large dark areas. A dispersion (water-based) varnish or a lamination prevents this. Sappi lists dispersion, UV and spot varnishes as compatible with the Magno range.

If people need to write on the piece (a reply card, a voucher, an appointment card), choose uncoated or C1S with the uncoated side for writing.

 

Which to choose for common jobs

• Flyers and posters with photos: coated gloss or silk, 130 to 170 gsm
• Brochures: coated silk for inner pages, coated 250 to 300 gsm for the cover
• Business cards: coated matte or silk if the design is image-heavy; uncoated if you want texture or need people to write on them
• Letterheads and envelopes: uncoated, because they go through office printers and get written on
• Menus: coated with lamination if they get handled every day

 

Before you send your file

1. Ask your printer which paper they will use and which ICC profile to convert to.
2. Pick Pantone colors from the C or U guide that matches the paper.
3. Keep total ink under the profile's limit (300% for the v3 profiles).
4. Add bleed. Our guide to bleed in printing explains how much and why.
5. If the piece folds and the paper is thicker than about 135 µm, ask for scoring.

If you design in Grafista, download your design as a PDF and send the printer this checklist along with it.

 

Sources

• Sappi, Magno Gloss datasheet 2025
• Sappi, Magno Satin datasheet 2025
• Sappi, Magno Matt datasheet 2025
• Arctic Paper, Munken Pure technical specification
• European Color Initiative, ICC profiles (see Downloads)
• Print.App, ISO Coated v2 (ECI) profile summary (330% ink limit)
• International Color Consortium, GRACoL2013_CRPC6 profile registry entry
• Pantone, Coated and Uncoated in the Pantone Graphics System
• ISO, ISO 12647-2:2013 sample (printing conditions and TVI curves)
• Heidelberg, Further development of ISO 12647-2:2013 (FOGRA51 and FOGRA52 TVI values)