When you order litho printing with Marstan Press, we have many paper types to choose from. As you would expect from a company which prides itself on eco-friendly products most of our papers are FSC® certified. Here is a brief guide to the different types and finishes of paper stock available.
Paper (or board) coated on one or both sides with a mixture of china clay, latex and other loadings to fill up surface pits and improve the printing surface. There are a variety of coating methods, the most common on-machine coating method being roll coating. Off-machine processes include blade coating, air-knife coating, the traditional brush coating, or combinations of these types. A very high quality form of off-machine coating is cast coating.
Silk Finish (aka Satin)
A smooth, delicately embossed finished paper with sheen – probably the most common of paper types.
A dull, clay-coated paper without gloss or lustre.
A glossy coated finish, which allows ink to dry quickly.
Uncoated Paper (aka Offset)
Paper that has not had a final coating applied for smoothness. Uncoated paper is absorbent, hence the printed appearance is flatter than on coated stocks.
There are different definitions of the term “recycled” within the industry, so it is important to check the fibre detail of a material. It is quite normal, for example, for a paper to be called ‘recycled’ when only a small percentage of the fibre is actually recycled.
- Post-consumer waste is when the product has reached the end consumer, and is then recycled.
- Pre-consumer waste (sometimes known as post-industrial waste) describes printers’ waste, such as off-cuts and unused copies which may have been over-ordered.
Processing recovered paper
Superficially it’s quite straightforward: waste paper and board is collected, sorted and then sold for re-use. Next, the fibre is pulped, screened (to remove foreign particles, contaminants, and fibres not fit for re-use) and then de-inked. It may or may not then be re-bleached.
The extent to which each of these processes is undertaken depends on the quality of the final product. Fibre for reuse in higher quality materials is chosen accordingly: higher quality waste will be used in higher quality new materials; lower grade waste will go into newsprint or packaging. Around 70% of the original volume of recovered paper will be used in a new material.
- Waste paper and board is collected and sorted by specialists at central operations.
- The sorted waste is sold to paper mills for processing and re-use.
- The waste is pulped, screened and then either de-inked or dispersed. De-inking is done using sodium hydroxide, the main ingredient in soap and the same chemical which is used for washing vegetables. The residual sludge from the de-inking process is used as fertiliser or fuel. Dispersal spreads the ink rather than removing it.
- According to end use, the pulp may be bleached. The main chemical for bleaching recycled fibre is hydrogen peroxide, the same chemical which is used to bleach virgin fibre.