Photo: Lorenzo Pellegrino
Among the various manufacturing steps, all of which are invisible to the public, there is one that is particularly long and delicate. It is referred to as tumbling, it originated in the 1950s and is still today an essential part of the fascinating journey that leads to the creation of a new frame.
Round, irregular, butterfly or cat-eye. And then metal or acetate, black or coloured: these are the infinite ways in which frames can surround our eyes, bringing the best out in them. Not everyone knows, however, which and how many special processes go into making a pair of glasses. Lara Marogna, Group Style & Product Development at Marcolin, explains one of the most important and delicate processes: tumbling. “Its name comes from the machine that is used, the tumbler. This is the name given to the cylindrical machine, also known as the ‘barrel’, which is divided into tanks inside which, once the shaping is complete, the frame fronts and temples that will later make up the glasses are inserted, together with pieces of beech and birch wood of different sizes and balls of abrasive paste. At this point, the machine is closed and started up: the tumbler starts to turn on itself at a speed that can vary depending on the material (metal or acetate), and with each rotation, by dropping and rubbing, pieces of wood and abrasive pastes do the job of roughing, polishing and final buffing of the frames.” A long job because, for each of the three stages, the tumbler runs continuously for 12 to 14 hours.
At each step, when the tumbler is unloaded, the workers check the frames one by one. And when it’s time to fill it back up, they must know how to perfectly dose the pieces of wood and paste that make up the polishing material mixture. And they can do this by checking by touch that it is neither too dry nor too oily; therefore, experience and knowledge of materials are required. It is precisely the right balance of these ingredients that gives an excellent result. A pair of glasses in which every detail of the frame is perfect for its function, therefore resistant but also aesthetically impeccable.” And Laura Marogna, who began her professional career in the world of jewellery, knows that it is from the care of these stages, which take place behind the scenes in a factory, that we can obtain a glamorous and elegant product, capable of making us dream and enhancing our personal style.
After this period, the tumbler is opened and the frames are checked one by one (for the uninitiated, it is surprising to see how at each step, the frames are more beautiful and shinier). Next, they are put into another tumbler, where the next stage runs for another 12-14 hours. In all, the process takes four days to achieve the result of a perfectly smooth and shiny frame. Ready to be finished and leave the factory.
It is not, however, a purely mechanical process, where the tumbler does everything: what makes the difference in tumbling is the human touch, thanks to the eyes and hands of the workers who manage and follow the whole process.