When the painting “St. John the Evangelist and St. Francis of Assisi” entered the Uffizi collection as part of a donation, it was assumed to be a copy executed by the workshop or by disciples of El Greco. Indeed only a few people had seen it before and scholars had not even examined it, so for several years it was kept in the storage rooms of the Uffizi and not displayed. The analysis carried out by Art-Test prior to the restoration by Lisa Venerosi Pesciolini in 2010, found in the canvas all the technical characteristics of the master and his unique pictorial language. In this case, only non-destructive investigations have been performed: the X-ray and IR reflectography scan revealed, beneath the outermost varnish layer, a complex reworking of the figures, with numerous “pentimenti”, changes made by the master in the course of work; and other important autograph signs such as the use of brushes of various types and sizes. The relative radiopacity is also peculiar to the paintings of El Greco, i.e. above all the inimitable insistent brushstrokes for the drafting of flesh tones. For the attribution of a painting it’s very important to identify a strong similarity with similar works of the painter, especially in the inner layers which are not visible to the naked eye. Indeed the disciples, but also copyists and counterfeiters, which flourished especially in the nineteenth century after El Greco was rediscovered, generally arrive to reproduce with great fidelity the outward appearance, but the internal structure, being hidden and tied to the way of working of the artist, is much more difficult to imitate and reproduce. In the case of El Greco, not only the inner layers, but also the surface itself have a very specific personal character, a complex work of a drafting extraordinarily layered, rich, sophisticated, expertly built with precious colour: lapis lazuli, lacquer work with a particular technique, which allows to obtain deep tones, cold, as visible in macro images and as noted by the investigations in ED-XRF. This uniqueness made it always very difficult for disciples and copiers to imitate the master. But it makes it easier for us, after the results of the tests, to state with certainty that this stunning painting, now in the rooms of the Uffizi dedicate to foreign painters of the XVI and XVII centuries, comes from the hands of El Greco himself.
The survey results were published by the magazine “Art e Dossier” of February 2012.