#PrintingProcesses: Gravure Printing
Let’s move on with our new series #PrintingProcesses and one of the oldest printing processes still in use today: gravure printing. As early as the Middle Ages, people produced copperplate engravings (a graphic gravure printing process) with an image depicted in the recesses. Since then, gravure printing has developed over a long time and is used today for banknotes, cosmetics packaging, magazines and many more.
Are you a newcomer to the world of printing and don’t know where to start? Or maybe just a devoted print enthusiast who wants to freshen up on the basics? Then you’ve come to the right place! With our series #PrintingProcesses we’re introducing you to all the basic – yet very important – techniques and fundamental knowledge of the print technologies we know and utilize to this day. In this third edition it’s all about gravure printing, one of the oldest printing processes still in use today.
From the First Printing Plates to Print Runs of More Than 300,000 Copies
Even if the first printing plates were developed in the Middle Ages – the cornerstone for gravure printing was laid in 1719, when the Frankfurt-based Jakob Christoph Le Bron invented the three-colour printing with its copper mezzotint technique. He used the depressions of these printing plates for ink transfers and enabled the printing of up to 1000 copies per day.
Later on, Jacob Perkins has patented the steel engraving that provides finer print results compared to the previously used copper. Fonts and images were thus reproduced more clearly and finely. Until today gravure printing has been improved properly but how does it work exactly?
Gravure printing is a demanding printing process in which the print image is engraved as a depression in a printing plate and dipped in ink. Since only the resulting indentation is to be printed, the excess ink is removed to a basin with a squeegee or wiper and only sticks to the deeper areas, the actual print elements. In the last step the ink is transferred to the printing medium with strong pressure and the help of the absorbent force of the paper.
After the printing, the paper must be dried, as the substrate often needs to be damp to accept the ink. Together with the wiped ink the solvents from the printing ink can be recycled and reused.
The colour depth of the resulting print image incidentally depends on the depth of the depressions, the so-called cups which enable the representation of different color shades.
There are different techniques for gravure printing: rotary printing and sheet-fed printing are the most famous one. The latter is much less common and is only used for special jobs such as printing varnishes or metallic inks. Rotary printing (from the roll), on the other hand, is very widespread and is used especially for the production of high print runs of more than 300,000 copies. The following video shows the mechanism behind gravure printing:
A Printing Process with High Quality Standards
Now you know how gravure printing was invented and how it works but what makes it so popular and special?
You can recognise a gravure print by the serrated edge of the letters, the so-called sawtooth effect, which is created by the cups. Since the substrate draws ink not only from a small part but from the entire cup, there are no sharp edges. Besides, the substrate has a strikingly smooth and soft surface, whether it’s made of film or paper. Maybe you recognised it from how a magazine feels in your hands.
Gravure printing is characterised by high quality and durability. The dimensions of the cups determine the ink distribution and define exactly how much ink the cylinder takes up at which point. This precision affects the halftones, the colour nuances of your printed product. Gravure printing actually reproduces the colour gradations.
Even though the gravure printing process is very old, it still maintains its usefulness today with high print qualities, an even ink application and rich colour depths. Therefore it will be quite a while before gravure is seen only as a historical printing process. Until then take a look at our other episodes of #PrintingProfessions.