What are the various types of papers for printing? And what characteristics must be taken into account when choosing the most suitable support for your needs? The weight, the degree of whiteness, the gloss of the paper are factors that can influence the color rendering, the definition of the print, and, of course, the overall result.
Introduction: what is paper made of?
In the vast majority of cases, paper is made up of a set of fibers of vegetable origin, from which what is called "pulp" or "pulp" is produced. The most widely used fibers are those of wood or, alternatively, of hemp, bamboo, straw and cotton.
The cell walls of the fibers are composed of almost 45% cellulose, a polysaccharide from which many derivatives are obtained, from rayon to viscose to the same paper.
The wood pulp (or mechanical pulp) is made by means of a totally mechanical process of rubbing (chipping) of the wood from the bark of trees such as fir or birch.
In addition to paper, cellophane can also be obtained from wood pulp.
Instead, chemical paper is produced using chemicals that remove a greater amount of lignin, thus obtaining a higher quality pulp. In other words, a pulp made up of 90% cellulose and 10% wood paper.
At the end of the refining process, the paste is transformed into a paper roll.
Chemical paper allows for superior quality papers, such as those used to print magazines.
The weight of the paper
When we talk about grammage, this characteristic is very often confused with the thickness of the paper. But they have nothing to do with it: the grammage represents the consistency of the paper, which is conventionally measured according to the weight in grams of a sheet of one square meter.
We take 80 gr offset paper as an example, that is, the traditional sheets of paper that we use to make photocopies or to print with a normal printer: 80 grams indicate the weight of a sheet of dimension 1 meter by 1 meter.
The higher the grammage, the greater the stiffness and thickness of the paper. However, not necessarily two types of papers of the same weight also have the same thickness and the same stiffness: each type of paper has its specific characteristics that differentiate it from other papers. In particular, it is above all the amount of wood fiber and the type of treatment carried out to obtain the paper, the aspects that determine this difference.
These are the varieties of paper, from the "thinnest" to the "thickest":
bible paper, between 25 and 35 grams per square meter
light paper, 60 to 90 grams (the classic photocopy paper)
printing paper, between 90 and 150 grams (flyers, brochures, posters, etc.)
cardboard, starting at 200 grams (business cards, presentation folders, etc. banner cards
The bright
Given that, as we have just said, each paper is the result of different chemical processes and different types and gradations of fibers, the color result may vary based on all the factors involved in the production. Thus, each paper has a different degree of whiteness and this influences the diffusion of light and the perception of shades. All these characteristics intervene in what is defined "whiteness" of the paper.
Consequently, the same color printed on two papers of different whiteness will be different but not necessarily visible to the naked eye. Color rendering depends on the characteristics of the paper, of course.
Paper finish: coated and gloss
finish-paper-gloss-matte
Another substantial difference is between coated and uncoated paper.
Uncoated paper, also called offset or letter paper, does not have any type of surface varnish. While in the second case, a layer of mineral pigments is applied over the entire surface that allows the ink to dry faster.
Printing on coated paper has a better visualization compared to printing on offset paper, because the coating layer makes the result more attractive and the colors sharper and "risen".
Coated paper may appear
brightness
matte, coated paper without mechanical treatments
Standard ISO 12647 - 2
The international standard ISO 12647-2 of 2007 establishes the technical specifications and tolerances for color reproduction for offset printing and others: the values and tolerances necessary to standardize the printing process are specified and the paper media is classified into five types according to their grammage, whiteness for its color and brightness.
In the ISO 12647-2: 1996 standard these 5 types of paper were established:
Type 1: Woodfree-coated, Gloss-coated: white grade 89, weight 115 g / m2: ECI profile: ISO Coated v2, with Adobe software Color profile Coated FOGRA 39 (ISO 12647-2 : 2004)
Type 2: Matte-coated, white grade 89, weight 115 g / m2: ECI profile: ISO Coated v2, with Adobe software Color profile Coated FOGRA 39 (ISO 12647-2: 2004)
Type 3: Gloss-coated, Web: white grade 70, weight 70 g / m2: ECI profile: ISO Web Coated v2, with Adobe software Web Coated FOGRA 28 color profile (ISO 12647-2 : 2004)
Type 4: Uncoated (Uncoated, White), white, white grade 93, weight 115 g / m2: ECI profile: ISO Uncoated, with Adobe software Uncoated FOGRA 29 color profile (ISO 12647-2: 2004)
Type 5: Slightly Yellowish Uncoated (Uncoated, Slightly Yellowish), White Grade 73, Weight 115 g / m2: ECI Profile: ISO Uncoated Yellowish.
The following 2013 standard integrates the previous one with 8 other types of paper:
Premium coated (on heatset and flatbed machines - Wood-free coated, Gloss, Semi-Matte, Matte)
Improved coated (in heatset - Medium weight coated, Light weight coated)
Standard glossy coated (in heatset - Light weight coated, Gloss, Semi-Matte)
Standard matte and Semi-matte coated (in heatset - Machine finished coated, Light weight coated, Semi-Matte)
Wood-free uncoated (in heatset and flatbed machines - Offset, Wood-free uncoated)
Super calendered uncoated (in heatset - Super calendered)
Improved uncoated (in heatset in heatset - Uncoated mechanical improved, Improved newsprint)
Standard uncoated (in heatset - Standard newsprint) The hand
Finally, we are going to explain what is meant by “hand of the paper”, also called volume. This is the relationship between the weight of the paper and the thickness of the folio. The thickness or thickness of the paper is measured in microns (through the micrometer).
From the relationship between thickness and grammage, the volume is obtained, that is, the density of the paper when touched with hands (hence the expression “hand of the paper”).
Now that you know all the essential characteristics of paper, you can print your products
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