How is Coloured Paper Made?

January 19 2021

When we think of paper, it’s the white version that immediately springs to mind – and indeed, the pure whiteness of today’s finest papers is a testament to the human ingenuity that can transform trees and other plant fibres into an incredibly pure, smooth and snow-white substrate that has countless applications.

But of course, not all paper is white.  Coloured paper forms the basis for many practical and creative disciplines, from education and corporate uses through to book binding, packaging design, specialist printing and art.

In its infancy, coloured paper was only available in a limited range of primary and pastel colours but today, the spectrum is almost infinite, boasting subtle variations in tone and shade that afford precision colour matching and allow physical print to dovetail more closely with digital technology than ever before.

But how is coloured paper made? 

How can a substrate that starts its life as neutral-coloured wood pulp be transformed into a versatile material that comes in just about every colour under the sun?

The process is simpler than you might expect, albeit one that has been repeatedly refined over centuries in order to deliver the kind of quality, high-performing papers we have at our disposal today.

 

All paper starts out as vegetable fibre.  Whether it’s wood, cotton, bamboo, hemp, or even sugar cane, and whether these fibres are virgin or recycled, the first step in all paper making is the creation of pulp or stock.

In this process, plant fibres are macerated using either mechanical or chemical processes, and mixed with water to create a soggy suspension.

What follows next is a process of spreading, drying and compressing or rolling the pulp so that it forms a tightly compressed sheet that is both strong and flexible.

Paper can be made by hand using this process, but obviously the vast majority of the paper we use is made in huge machines that take in pulp at one end, and pass it along a complex series of drying belts and rollers until a reel of uniform, smooth paper emerges at the other end.

All sorts of compounds and materials can be added to paper stock to change the properties of the finished paper – things like surface coatings and sizes to change the way the paper behaves once its printed, and of course dyes to change its colour.

To produce white paper, the stock must be bleached to remove the natural pigments – and this is also true for pale coloured papers, where dyes must be added to bleached paperstock in order to achieve the correct shade.  For dark coloured papers, the unbleached stock can be used.

Alternatively, paper may be dyed later in the process, on a machine called a sizing press.  Sizing is the application of substances like starch to the surface of the paper, to improve stiffness and strength.  Dye can be sprayed onto the paper at this point, before the paper is dried and rolled to finish.

Coloured paper can also be made using the coating process, where the base paper is run through a ‘bath’ of special clay coating that improves the smoothness of the paper surface and makes it less porous.  This means the paper absorbs less of the ink when printed, resulting in a crisper finish.

Pigments can be added to the clay to make a coloured coated paper that is then passed through heavy steel rollers called calenders to produce an ultra-smooth, uniform finish.

The majority of coloured papers, including our Gmund Colours range, are produced using the dyed paperstock method.  At their mill in Germany, Gmund use a machine called a Hollander Beater to macerate the paper stock and combine it with the dye for superior consistency and saturation in the finished product.

As well as an array of captivating colours, this range showcases some of the most advanced finishing techniques that allow Gmund Colours customers to select from a range of incredible papers including metallic, fabric textured, transparent, food safe and box materials.

Want to know more about the Gmund Colors Collection?  Head over to this page

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