Coated paper has been coated with a surface sealant, typically clay, to impart certain qualities to the paper, including weight, surface gloss, smoothness or reduced ink absorbency. The coating on the paper reduces dot gain by not allowing the ink to absorb into the paper. This allows for cleaner crisper printing, especially in photos, blends and fine details. Coated papers come in numerous options: gloss, matte, dull and satin finish.
Gloss — gloss coated paper has a high sheen. Gloss papers have less bulk and opacity and are typically less expensive than dull & matte paper of equal thickness. Gloss coatings reduce ink absorption, which give the sheet an excellent color definition.
Satin — a satin coating is a less shiny coated finish. It has a lower gloss level than gloss finish, yet a higher gloss level than matte finish. Colors are sharp and vivid.
Matte — a matte coated paper is a non-glossy, flat looking paper with very little sheen. Matte papers are more opaque, contain greater bulk, and are higher in cost. The coating still keeps much of the ink from being absorbed by the paper, which produces excellent, vibrant color.
Dull — a dull finish coated paper is a smooth surface paper that is low in gloss. Dull coated paper can fall between matte and glossy paper depending on the manufacturer.
Uncoated paper stock is paper that has not been coated with a surface sealant. Inks dry by absorbing into the paper. This paper type can dull the colors that are printed. Uncoated papers comprise a vast number of paper types and are available in a variety of surfaces, both smooth and textured. Some of the common types are wove or smooth, laid and linen.
Wove or Smooth — this has a very smooth surface.
Laid — laid paper is created with textured lines on its surface. This finish is used mostly for business stationery elements, like letterhead, envelopes and business cards.
Linen — similar to a laid finish, this paper has textured lines on the surface of the sheet, but they are finer and more regular than those that appear on a laid finish stock. This paper is also used frequently for business stationery.
Coated One Side and Coated Two Sides
This paper is commonly referred to as C1S (coated one side) or C2S (coated two sides). In a C1S paper the coating has been applied to only one side of the paper. C2S the coating is on both sides. Typically the coated side is glossy. You will find this type of paper used primarily on postcards. It gives a glossy feel to the front of the card while using the back uncoated side for addressing.
The weight of a paper refers to its thickness and is typically measured in pounds (such as 20#) and points (such as 10 PT). The higher the number, the thicker the paper for that “type” of paper. Paper weights in commercial printing can be very confusing. For example, a sheet of 20# bond (probably what you use on your inkjet printer) is about the same thickness as a sheet of 50# offset.
There are three general paper categories used to describe the basis weight of a paper: writing, text and cover.
Writing — a letterhead-weight stock, typically 24# or 28# writing, and often has a watermark.
Text — is thicker than a writing paper, but not as thick as a cover paper (card stock). Text-weight paper is usually a 70#, 80# or 100# text.
Cover — Cover stocks are heavy in weight, rigid and not easily folded. Common weights for cover stocks include: 65#, 80#, 100#, 120#, and 12pt.
A paper’s opacity is determined by its weight, ingredients and absorbency. A paper’s opacity determines how much printing will show through on the reverse side of a sheet. Opacity is expressed in terms of its percentage of reflection. Complete opacity is 100% and complete transparency is 0%.
The brightness of a sheet of paper measures the percentage of a wavelength of blue light it reflects. The brightness of a piece of paper is typically expressed on a scale of 1 to 100 with 100 being the brightest. The brightness of a paper affects readability, the perception of ink color and the contrast between light and dark hues.