The Paper Paper Making Process

The paper making process starts with logs that are debarked. Once they have had the tree bark thoroughly removed they are turned into wood chips and then placed in digesters. The best way to describe a digester is like a huge pressure cooker. This cooking process separates cellulose fiber (number 1 paper-making ingredient) from the gums, resins and other impure materials that bind them together. These impurities are then disposed of, the cellulose is filtered out, and chemical wood pulp is created to be used for paper-making.

Many stages of bleaching are next, which is done to create whiter the pulp. Typically ultra-bright white papers are sold at premium prices. This is why paper mills strive for whiteness through bleaching. Constant quality checks are mandatory along the way to insure maximum brightness without damage to fiber strength. Over-bleaching can weaken paper in much the same way that it can ruin clothing.

After bleaching, the pulp is refined and blended with other paper making materials, using a special, predetermined formula for each grade. Then it is piped onto the “wet end” of the paper machine. It is interesting to note that paper is 99% filtered water and only 1% paper making ingredients in the beginning. But, as the paper moves toward the dry end of the machine, all but 5% of this water is removed by gravity, mechanical means, and evaporation through heated drums. Some “plain” papers require no further finishing, while others can be coated on the paper machine. For others, the coating takes place off the paper machine as a separate operation. Generally, coated papers are super calendared by being passed between a series of polished steel and compressed cotton rollers, under pressure, to increase their gloss and smoothness.

Different Paper Types

UNCOATED OR “PLAIN” PAPERS ANTIQUE

An antique surface is relatively rough, and the paper itself is bulky. It and other antique papers are limited to type and line engravings by letterpress and may be used for the reproduction of simple halftones by offset. Commercially published books are an important end use, because high bulk is generally an important consideration. M.F (MACHINE FINISH) M. F papers are used for basically the same purposes as antique, except that they are smoother and have less bulk. Thus, they can be printed with more detailed illustrations. WOVE OFFSET Wove Offset is an uncoated paper with a smooth surface that can be used as an economical text paper. Scott Offset is an example of this quality.

COATED PAPERS

MATTE

Matte paper has a layer of mineral particles called “coating pigments” applied to its surface which makes it smoother and more ink receptive. Designed for both sheet-fed and web offset printing, these papers are suitable for single and process color work.

COATED

This paper is created when a much thicker layer or layers of coatings are applied, imparting greater smoothness and, consequently, better printing quality than that of pigmented paper. It comes in gloss and dull surfaces, as well as embossed finishes. Top quality grades like Cameo will reproduce the finest halftones by offset lithography. Some coated papers are made to meet the requirements of web offset printing, while others are suitable for gravure.

CAST-COATED

The highest sheen finish, known as cast coating, results in a mirror-like finish with exception high gloss, giving the finest possible printing surface. One of my favorite cast coated materials to print on is Astralux Coated Cover. It is a perfect high gloss cast coated grade, and delivers great ink absorbency and can be used for all lightweight packaging applications.

Coated Two Sides

A genuine cast coated surface, allowing ink to absorb and lay perfectly. Tints A range of tinted board to complement the Astralux range. Paper Astralux provides an superior ultra gloss cast coated surface. A brand that sets quality standards with it’s superb colour reproduction. Weights 60 lb. C/IS 8pt. C/IS lOpt. C/IS I2pt. C/IS Opt. CI2S l2pt. CI2S Ask your local paper merchant for a free swatch book an look at the finish!! Unbelievably smooth and glossy.

Related Posts