Creating a book is a complex task, as creative as it is technical. The three most important elements are the manuscript, the cover image and of course the choice of paper. The type of paper will directly impact your readers’ tactile and visual experience of your book.
Choosing your paper is as important as choosing your words. A paper is characterized by its composition, its weight and its finish. There is no standard paper for all types of printing. Paper manufacturers offer a wide selection of paper stocks, and over time some of these have become standards for certain media. For instance, you would not want to print a wedding invitation on the same paper as you’d print a newspaper.
In this article, we will provide a complete overview of the variety of papers used in the book industry.
Paper can be produced from all kinds of natural fibers that contain cellulose: from the cotton rags which were used as the first kinds of paper, to hemp for Bible paper. You can also find papers produced from bamboo, coconut fibers, papyrus, and even straw. That said, the publishing industry mainly uses papers produced from wood fibers.
At Rapido, we offer a wide range of interior papers for your book and we are happy to assist you to make the best decision.
First of all, there are two main categories of paper: uncoated papers and coated papers.
Coated papers are papers whose microporous fibers are covered by a thin layer of minerals for a smoother, more opaque and whiter appearance. This layer also ensures better printability, especially for images that require higher-quality rendering. The appearance of coated paper can be matte, satin (silk) or gloss.
Uncoated papers are papers whose surface consists only of fibers. More porous and more irregular, this surface provides the best reading comfort for black and white books.
A mineral layer is added to the paper at the end of the production process to make it a coated paper. This gives the paper that smoother, whiter appearance. The finish of this layer depends on the calendering carried out on the surface of the paper after adding the mineral layer. The calenders are rolls whose surface resembles a grate. With their lateral movement, they exert a kind of sanding on the surface of the paper. If you don’t use it, the paper will be matte. If you give it a slight sideways swing, it will be satin, and if it is faster, the surface of the paper will be glossy.
In the past this layer was made of kaolin, but it’s now been replaced by calcium carbonate because of its affordability. However, kaolin had much better mechanical properties: smoother surface, better fiber coverage and less likely to curl in heatset printing (rotary offset).
Coated paper will have a surface free of irregularities and will perform best in books with illustrations. It is also used for magazines and advertising materials. Coated paper is always softer and finer than uncoated papers, since the fibers have been flattened.
You can sometimes use the coated paper in black and white books, for what are called inserts, that is to say notebooks of 8 or 16 pages in which are grouped all the illustrations of a given book. For this purpose, we recommend using a Silk 80lb/160M paper stock for an insert in books in 6 X 9 format or smaller.
Uncoated paper is commonly used for writing paper (office paper), newspapers, and black and white books.
Offset paper is a type of uncoated paper. It may have traces of wood, or it may come from a recycling process. In all cases, it is characterized by its irregular surface, its matte appearance, its lower whiteness, its higher transparency and its lower cost.
The pulp can come from recycled paper or from new fibers. It is said to be mechanical pulp if the wood is processed by simple grinding, or chemical pulp if it is produced by heating and adding chemicals. Some papers contain 100% recycled pulp, such as the Enviro Book, others may contain a greater or lesser proportion of recycled pulp to supplement the new fibers. To see all of our papers and recommendations by book type, click here.
Rapido also offers cream paper, sometimes referred to as opaque paper. This type of interior paper is often used for poetry.
Note: Recycled papers have lower whiteness because they contain impurities. From one production to another, the nature of the used paper inputs is never quite the same and despite the rigor of industrial processes there may be slight variations. We do not recommend this type of paper for color prints, but if your book illustrations have little color and you want a more creative-looking result, it will allow you to make the book look a bit more raw.
Bulky paper is part of offset papers. Compared to standard offset paper, this paper is characterized by much bulkier fibers. Bulky paper can be up to twice as thick as standard offset paper for the equal weight. Note that this paper is rather difficult to find in North America because of low demand.
Contrary to popular belief, recycled paper is not the universal panacea that would allow us to stop cutting trees to produce paper. First of all, paper is only recyclable three times – once or twice for printing paper – for quality reasons. That said, it is possible to recycle it again after that to produce cardboard for packaging and materials for construction such as gypsum board or even insulation of houses with cellulose wadding.
Recycled paper is an excellent outlet that avoids the destruction of paper. This is all the more important as paper is an excellent trap for CO2 molecules which will only be released if it is destroyed by combustion.
Most often, people choose to use this paper because it is less expensive or out of ecological concern.
Environmentally friendly paper is not necessarily recycled paper. This type of paper must come from sustainably managed forests and has to meet the selection and treatment process criterias required by the FSC (Forest Stewardship Council) to ensure environmentally friendly use. The FSC label is used to authenticate the processes and origin of the paper used. Most papers used in North America are FSC certified as the logging and wood processing industry are increasingly incorporating environmental requirements.
What causes paper to yellow?
The yellowing of paper occurs when the paper comes in contact with the ambient air. Paper is made from plant fibers: cellulose, hemicellulose and lignin. Lignin, which gives paper its rigidity, tends to oxidize, and therefore to yellow in the “open air”. It’s the same principle you see with an apple when you peel it and eat it a few hours later. Less expensive papers such as newsprint and offset paper contain more lignin than coated papers and therefore tend to yellow faster. The papermaking process involves removing most of the lignin fibers by separating them from the cellulose. Previously, acids were used for this. Today, paper makers are more likely to use sodium hydrosulfite or ozone treatments for health and environmental reasons. Pollutants like acid have been eliminated, as they also shorten the life of the paper.
The cover paper is generally a single-sided coated paper weighing more than 224 g / m2. It is for this reason that it is classified under the category of coated stock, which in Quebec is also referred to as cardboard. Thicker, stronger and heavier than the inside paper, it is only used for the book cover.
At Rapido, we work with 3 types of cover papers:
- 10pt paper coated one side;
- 12pt paper coated one side;
- The 10 pt uncoated cream offset paper.
This paper is often used for poetry books to better match the color of the inner paper which is often cream offset paper. It also provides a creative edge for certain types of covers. However, the ink load on these papers must be limited because they are prone to scratching.
Direction of grain, or direction of paper fibers
Books smaller than or equal to 6 X 9 ” should always be printed in the direction of the grain, otherwise the reader will have difficulty turning the pages. For large formats, when the width is at least 8 “, the problem is hardly noticeable.
At Rapido all covers are printed in the direction of the paper grain and all the interiors of black and white books are also printed.
But what exactly does it mean to print in the direction of the paper grain? It means that the cellulose fibers are always parallel to the spine of the book. This makes the book more flexible and allows the cover to open more easily. If you looked at the paper with a microscope, you might find that the paper is a tangle of fibers, similar to hairs. In the papermaking process, fibers are placed in the direction of the paper machine.
Cover curvature and paper thickness
Many people think that by using 12 point paper instead of 10 point paper, the curvature effect of the cover will be reduced. However, this is not true. This unsightly effect can have several causes: poor production conditions, humidity and temperature differences in the production process and then in the transport of the book. Moisture is often the culprit of this curvature. A good printer should be able to control the moisture levels properly, except when the weather conditions are too unstable such as in extreme cold or stormy weather.
When books have been produced under optimal conditions and have been well packaged, this phenomenon tends to disappear as soon as the weather conditions stabilize.
Nothing better than a little experiment to gain a better understanding: place a sheet of plywood on trestles and apply a coat of water-based paint. After a few hours of drying, you will observe a significant curvature of the wood. If after drying you then paint the other side of the board with the same paint, it will return to its original shape. So, you might think it would be easier to laminate both sides of the cover paper? Unfortunately, that would be impossible for the simple reason that the glue would no longer attach properly to the cover.
What is paper grammage?
Grammage is a measure of mass per unit area, or grams per square meter (g / m2). The lower the grammage, the lighter and softer the paper. The higher it is, the heavier and stiffer the paper. The grammage is therefore equivalent to the weight per square meter of surface. The choice of paper weight is almost as important as the choice of the paper itself. In Quebec, the measurement in M, and lbs is more readily used in English-speaking Canada. The math is a bit complicated. Remember that 140M paper is roughly equivalent to 100 gsm paper and 110M is roughly 80 gsm.
Print with Rapido Books
You can see our recommendations for different papers by type of book here or contact our team of printing professionals now.
No description can replace the tactile and visual experience of being able to see and touch paper physically. That’s why you can fill out the form below and receive your free paper sample.