Credit: Jil Sander
Embossing refers to relief printing, one of the most common and distinctive techniques in leather processing. Whenever the grain of the leather has a three-dimensional processing, creativity meets precision mechanics, giving life to surfaces with the most disparate patterns.
But how is embossed leather created? What are the technologies that make it possible? We asked Leonardo Bergozza of Bergi, a Venetian company based in Arzignano, in the heart of the Veneto tanning district, which for over 60 years has been a point of reference in the production of machinery for tanneries serving the automotive, furniture and luxury fashion sectors.
Embossed leather is a subcategory of printed leather: it is leather with a relief print, used for example to reproduce python or crocodile effects, to imprint decorative designs or to obtain the classic dollar print, the texture that we see on many luxury bags. The customization possibilities are almost endless.
The relief is obtained by applying heat and pressure to the leather using a mold engraved with the desired pattern. Printing can be done with a plate or a roller, depending on the machine used. The old plate presses use engraved plates, while today the most used machines are rotary roller presses. “Unlike plate presses, with rotary presses there is no risk of overlapping the design, because the roller rotates continuously: the leather flows through the machine and the design remains uniform,” explains Bergozza.
To obtain a quality print, there are three fundamental parameters: the impression time, the temperature of the metal roller, and the pressure, essential for a high definition of the pattern to be printed. The leather then passes between two rollers: the engraved one, heated by an oil circuit that guarantees a uniform temperature, and the counter-pressure roller. The position of the latter can be adjusted, allowing for “contact” printing, applying real pressure, or “thickness” printing, only touching the tips of the grain of the leather and obtaining different effects.
The engraving method of the rollers also plays a key role. “The rollers can be engraved by hand, but today laser engraving is preferred, also for economic reasons,” explains Bergozza. Although the design may be technically identical, rollers engraved by different manufacturers greatly influence the final result. It is precisely in this game of variables that embossed leather finds its uniqueness. Each technical choice generates different nuances, and each human intervention changes the appearance of the relief print. This is why, even when faced with the same design, each embossed leather will be slightly different, unrepeatable.
