Chirale for Studio Silice: a new digital process for restoring Artistic Stained-Glass Windows

Studio Silice, owned by Anna Preziosi, is an artisan business with its workshop in a prestigious location, in the heart of the Rione Monti in Rome, where original-design objects, artistic stained-glass windows and lamps are made through a skilled glasswork.

The mastery of historical and traditional techniques allows Studio Silice to offer a high-quality restoration service for ancient artistic stained-glass windows.

In carrying out contracts in this field, compliance with the strict rules governing restoration operations is essential.

Glass is, by definition, a fragile material, and the reconstruction of lost parts of a stained-glass window raises a series of problems.

On one hand, it is often impossible to recover original glass sheets, or even glass from the same era as the window being restored; on the other hand, even using colours and pigments compliant with the originals and treated according to period recipes, the authors’ design must be reproduced manually, imitating their style and “brushstroke”.

However well-crafted, a restoration is always a modern artefact different in material and design from the original.

In this perspective, the approach behind the experimentation-and-research project carried out by Chirale together with Anna Preziosi of Studio Silice aims to use photographic and digital-printing techniques to reproduce drawings and colours on glass, faithfully transferring the author’s original strokes and signs that represent the true artistic value of the artefact.

The Digital Innovation Hub of Rome offers the ideal environment for this kind of experimentation.

Some original samples were photographed by a professional photographer, in an environment with controlled and balanced lighting.

The digital images were processed through the Roland Rastering Image Processor VesaWorks and then printed using UV technology on the planar machine of our FabLab Ostiense.

The results were carefully assessed under different lighting conditions, and the process was further refined by leveraging Anna Preziosi’s irreplaceable sensibility and skills, achieving a chromatic rendering virtually indistinguishable from the original.

Colour management in digital-printing processes is a complex operation that requires the generation of suitable colour profiles to ensure that the chromatic perception of an average observer for a given image is the same on each device used to handle the file — from the camera to the print medium.

The classic method for generating print profiles is optimised for InkJet printing on traditional substrates such as photographic paper or vinyl materials like banners and adhesive films used in the visual communication sector.

The Roland system and especially the RIP VesaWorks software provide all the features needed to generate colour profiles for any kind of substrate, and at our lab we have often generated custom print profiles for textile materials used in haute-couture projects.

In this case, however, the problem was more complex, because colour perception had to be assessed both through the transparency of the glass and under reflected incident light, since a stained-glass window can be viewed from different angles and at different hours of the day, when the combination of incident and transmitted light can be very different.

The process was therefore much longer and more delicate, but in the end the result was more than satisfactory.

As the last step of the experimentation, the printing process had to be optimised to ensure pigment resistance and durability on the specific material used. As is known, glass does not offer an optimal substrate for inkjet printing; however, the use of UV technology and the possibility offered by our machine to apply the primer selectively through a dedicated print head made it possible to meet all the objectives.

The experimentation carried out for Studio Silice once again demonstrates the effectiveness and importance of our R&D model based on the Digital Innovation Hub structure.

The presence of a large number of new technologies and the wealth of experience and skills accumulated by the technicians and consultants who have worked with our lab for years made it possible to set up the project while preserving the values of the artisan process and, at the same time, exploiting the full potential of the new digital technologies.

The resulting innovative process combines the advantages of industrial technologies with the values of traditional craft processes.