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Cave drawings are the oldest remains of documents, drawn with pigments on a substrate. Writing surfaces made from inorganic materials, such as soapstone, from Ancient Egypt are also known. In Ancient Greece, people wrote on papyrus using soot brushes and a rubber solution. The papyrus was made from plant stalks, which were beaten flat, laid on top of one another in a criss-cross pattern and pressed. The word ‘paper’ comes from the Greek word ‘pápyros’. 

 

The invention of paper is attributed to a Chinese man called Cai Lun, who first described the now-familiar process of paper making in 200 BC. Back then, a paper-like material was produced from silk waste. Paper makers mixed this with hemp, old rags and tree bark. In the process, the cleaned fibres were mashed, boiled and soaked. Then, single layers were skimmed off with a sieve, dried, pressed and smoothed out, in the same way as in today’s process. This process resulted in a good-looking side and a sieve side. Deposits created a relatively homogeneous sheet of paper. 

 

In Europe, mass production of paper began as far back as the Middle Ages. This involved optimising the Chinese innovations. The chopping process, which had previously relied on manual or animal labour, was mechanised with paper mills. The first paper presses to arise were based on the practice of pressing grapes. The first German paper mill came into being in Nuremberg as early as 1390. Until the 19th Century, the fibres needed were extracted from used linens. The rag collectors and traders at the time supplied the paper mills with the raw materials they needed. In the second half of the century, decomposing and cleaning the fibres was replaced by chlorine bleaching (similar to the modern process of de-inking). This reduced the loss of fibres and allowed white paper to be made from coloured materials. 

 

The lack of old rags caused people to look around for alternatives and experiment. In 1843, the German Friedrich Gottlob Keller invented a process for producing paper from groundwood pulp. Groundwood pulp was produced together with water on a grinding stone. Soon, Keller developed a wood grinding machine in order to produce the raw material for good quality paper. The paper made from groundwood pulp later caused problems. Due to various residues of acidic substances, the development of air and humidity through chemical reactions led to yellowing, a reduction in tear resistance and wet strength, and therefore to the paper becoming brittle. This ultimately caused a lot of damage when it comes to written records between the 19th and 20th Centuries. 

 

Since 1980, paper has been produced without the use of acidic substances. The use of chemical additives creates paper that is resistant to ageing. 

 

The raw materials needed for paper production today are fibrous materials (e.g. groundwood pulp, pulps and especially recovered paper), sizing and impregnation (e.g. waxes, resins), fillers (e.g. gesso, chalk, titanium white) and auxiliaries (e.g. colourings). 

 

There are two types of fibrous material: primary fibres, which are being used in production for the first time, and secondary fibrous raw materials – recovered paper. Today, the secondary raw material recovered paper accounts for around 70% of the new paper produced. Because recovered paper has already been processed into paper, the fibres have already been milled at least once. Milling them again causes the fibres to suffer more damage. Recovered paper can be recycled an average of five or six times. Chemicals are used to de-ink the paper, i.e. to dissolve the coloured printing inks. 

 

We come into contact with paper in a wide range of forms every day. This might be as tissue paper in the hygiene sector (toilet paper, kitchen roll), graphical papers in art and image printing, newspaper, or corrugated paper and board. Despite the developments in IT technology, paper remains one of humanity’s most important inventions to this day.