In memory of Pietro Pedeferri (1938-2008)
The study of interference colors that may appear at the surface of a metallic material dates back to the early XIX century. At that time Leopoldo Nobili, an Italian scientist died in Florence in 1835, first studied and obtained colors on the surface of a lead plate with an electrochemical technique in the presence of an acid solution. His funerary monument reminds he was considered a promoter of physics, and inventor and master of metallochromic art. Nobili couldn't obtain colors on titanium, since it hadn't been discovered yet; but from that time on other studies followed, focusing on other metals, until titanium coloring by anodic oxidation was eventually introduced in 1960s. This technique provides an easy method to produce interference colors, but obtaining and modulating them with knowledge and sensitivity is a refined art mastered by no one but Pietro Pedeferri.
Pedeferri started working on titanium coloring in 1967 at Politecnico di Milano. After a few months, once the principles underlying the obtaining of colors were unveiled, he observed that titanium can maintain "memory" of the initial functioning conditions, and that this property allows to record motifs and images on its surface that Pedeferri called "appearances" in honor of Nobili. Since then, researching technical means to record moving liquid fronts or other natural phenomena and experimenting new expression potentialities in visual communications kept interlacing, drawing benefits one from the other. Bruno Munari wrote about Pedeferri's anodic oxidation technique, reminding how lithography, xylography or anodic oxidation – the technique is not important; the key is playing with a medium to communicate something, and the pleasure of making then reflects in the object of communication.
In the forty years that followed this blessed debut in metallochromic art, the range of colors and their saturation and lightness extended and increased, few square centimeters sheets became plates and compositions reaching one meter of size; it is now possible to selectively substitute some hues with others and, besides the more usual and stable ones, produce new hues that change in time. Knowing how to govern the surface color of titanium is the outcome of a deep, scientifically based knowledge of electrochemical, chemical and physical phenomena taking plate on the metal surface. much of scientific literature dedicated to rationalize and rigorously describe titanium anodic oxidation and its chromatic potential – and other things, as Pietro Pedeferri would say – is the result of his work, and of whom had the privilege of working with him and continue his studies of such a fascinating phenomenon.
At the same time, this method is a powerful painting technique. During the years, the experimental set-ups and obtained results were illustrated on journals and books and collected in exhibitions. They were presented in conferences on scientific and technological aspects of metal surface finishing, and in Italian and international seminars on the theme "Science and Art". The appearances on titanium had the honor to be awarded the international prize Science pour l'Art together with Benoît Mandelbrot's fractals in Paris, 1989, and to be inserted in the exhibition programs of the Fondazione Corrente di Milano (1996) and Triennale di Milano (2010). Thanks to his scientific findings in the field of the corrosion and protection of metals, as well as for artistic credits, Pedeferri became member of the Istituto Lombardo Accademia di Scienze e Lettere. In collaboration with Alberto Casiraghi and numerous poets, including Alda Merini, Annalisa Cima and Giancarlo Consonni, he produced more than two hundred limited edition "booklets" edited by Edizioni Pulcinoelefante, decorated with paintings on titanium. Over more than forty years, his works changed in drawings, colors, surface finishing and production techniques, but also conserved the "inner light" that gives them the "lightness of dawn". Which is their magic.
Extracted and translated from: M. V. Diamanti, B. Del Curto, MP. Pedeferri, Pietro Pedeferri: l'ossidazione anodica tra scienza e arte. La Metallurgia Italiana 7-8 (2013) 51-55.