Paper grades may seem like a world of abbreviations
The paper industry uses a lot of industry-specific abbreviations and terms, so it may seem like a jungle to get lost in. What do all these different words and letters mean, and which ones are the most important to keep track of? We will take a closer look at LWU, LWC, MWC, WF, and WC, and sort out what these terms stand for.
Paper grades
1
LWU paper
As the name indicates, LWU (Light Weight Uncoated) paper is produced with no extra coating. It has a smooth surface after being pressed through a calender. Another component that increases the smoothness is the amount of filler (pigment) added to the paper, which also improves the printing properties. LWU paper is versatile and often used in magazines, catalogues, and direct marketing among other things.
2
SC paper
Super-calendered Magazine Paper, SC, is an uncoated grade with high gloss, primarily used for the publication of consumer magazines, catalogues and advertising material. It is made from mechanical pulp with a large content of mineral filler. SC paper is also extra calendered (polished) compared to an LWU paper, giving it a higher gloss and a characteristic rustling sound when you turn the pages. This grade is split into sub-categories based on brightness: SC-A+, SC-A and SC-B.
3
LWC paper
Light Weight Coated paper, LWC, is a collective term for particularly lightweight paper stock (of grammages less than 60 g/m2) that has a surface coating layer. The coating consists of clay and binder agents, which are applied by a special coating unit. LWC paper is available in several varieties regarding brightness, opacity, and grammage, and is mainly used for magazines and other publications that require excellent printing quality.
4
MWC paper
MWC, Medium Weight Coated paper, features the same properties as LWC but is generally available in grammages over 80 gsm.
5
Wood-containing paper
When making a wood-containing paper, the majority of the raw material in the pulp production is wood, amounting to around 98 percent. Since a wood-containing paper contains a great deal of lignin, a substance in the wood’s cell walls, it yellows more quickly when exposed to daylight than a wood-free paper would. However, wood-containing paper also has many benefits, such as stiffness, thickness, cost-efficiency and low environmental impact.
6
Wood-free paper
The term wood-free paper does not mean that no wood is involved in the production. It refers to printing and writing paper made with less than 10% mechanical pulp. The chemical process for the manufacture of pulp for wood-free paper uses around 50 per cent wood. The benefit of wood-free paper is high brightness, but it comes at the cost of poorer opacity. WF paper is also referred to as “fine paper”.