How was the original painting discovered?

It all started when a client brought us a painting for inspection. The client had always suspected that the painting – a mediocre copy of Antoine de Favray’s portrait of Grand Master Pinto, found at the museum of St John’s Co-Cathedral – had been retouched, but had never imagined that there would be another full painting underneath.

The first cleaning test revealed a blank white base and no painting underneath – this was not normal and it was not easy to remove either. The base required stronger chemicals as it was a technique called bianchette – a mixture of linseed oil and white lead.

After applying a targeted cleaning substance, the white layer started to reveal another painting, different from the paint layer on the surface. At this stage, a painting would normally undergo a series of X-ray photography – however, X-rays do not penetrate white lead, so we decided to conduct further cleaning tests, taking random areas to try and figure out the composition and orientation of the older painting.

Initially only parts of the background were exposed – however, one of the tests revealed a pair of feet, while another showed dripping blood on the feet. These clues pointed to a religious subject, possibly a crucifixion. The next cleaning test was conducted in the area where we thought the face would be positioned – it was important to try and reveal these details in order to see how good the quality of the underlying painting actually was.

We then contacted the owner to decide whether to keep the surface painting or expose the one underneath.

Since the portrait of Grand Master Pinto was not painted by a great artistic hand, the owner chose to remove it and expose the painting underneath.

We are currently in the process of finalising the restoration.

What would have led an artist to paint over another painting?

It is quite common to find a painting underneath another – this year, I’ve had seven such occurrences. The recent Mattia Preti exhibition at the Grand Masters’ Palace, Valletta, featured a painting completed on a recycled canvas, which originally featured a portrait by Preti himself.

Canvases were not so easy to purchase and construct in the past, so they would be recycled if a painting wasn’t considered worth preserving. In other cases, the original painting would have been damaged and so an artist would be commissioned to paint it over.

In this case, the discovery was not so common since the painting underneath was not the same subject and neither of same orientation. However, we lack documentation, so it’s very difficult to know why the original crucifixion scene was painted over.

What have you discovered about the two paintings?

The original was painted upside down underneath the portrait of Grand Master Pinto. The subject is the crucifixion, with Christ on the cross right at the centre flanked by the Virgin Mary, Mary Magdalene and St John. It seems as though the painting dates to the early 18th century – the artist would have been in contact with the Roman milieu of the time and familiar with works by Benedetto Luti and Domenico Guidi. We are conducting more research and results which, together with the restoration process, will be published later on this year.

The second painting is a somewhat amateurish copy of Antoine de Favray’s portrait of Grand Master Pinto. A number of copies exist, including one at the Museum of the Order of St John in Clerkenwell, London.

What processes did the restoration involve?

The restoration process was complex since the cleaning involved the removal of oil overpaint and a bianchette layer, thus requiring two different cleaning systems. Bianchette is a very tough material to clean, so we first had to soften it with chemical poultices and then remove it by hand using a scalpel. This is a very delicate process as one mistake could damage the original painting. It took us five months to remove the overpainting.

We adhere to the ethics of conservation and during the whole restoration process, we used stable and reversible materials. Also, at a very close distance, our intervention is distinguishable from the original.

Was irreparable damage done by the second painting?

Before being overpainted, there was a substantial amount of losses in the original paint layer, which is probably why the painting was covered up in the first place – this could mean that the damage was present beforehand and not as a result of the later painting. Also, the paint layer had diagonally formed cracks, which seems to indicate that the painting was probably rolled up before being stretched on to the frame.

However, we decided that the painting was still worth restoring and could be reconstructed through faithful retouching.