- Restoration, of The Agony in the Garden with the Donor, Louis d’Orléans (1405-1408)
- Restoration, of The Wine of Saint Martin’s Day by Pieter Bruegel the Elder
- The Restoration of the two Equestrian Portraits by Velázquez
- Restoration of Ariadna
- The Restoration of Nero and Seneca by Eduardo Barrón
- The Restoration of Adam and Eve, by Dürer
- The Restoration of Philip II on Horseback by Rubens
- The Restoration of The Adoration of the Shepherds by Pietro da Cortona
- The Restoration of The Soult Immaculate Conception by Bartolomé Esteban Murillo
- The Restoration of The Purification of the Virgin in the Temple by Pedro de Campaña
- The Restoration of the 2nd and 3rd of May
In 2000, the Museo del Prado decided to restore the paintings and with this aim in mind convened an international symposium at the Museum, attended by art historians specialising in Goya and leading restorers.
In the restoration undertaken in 1941 the paintings had been given a coat of varnish which, due to the passing of time and inevitable oxidisation, had lost its transparency and turned into a yellow coating that obscured the original colours. Restoration of paintings should be undertaken when they are considered to be at physical risk or when the colours, glazes and other technical devices have become obscured or altered by dirt that has accumulated over the original surface. This was the case with The 2nd and The 3rd of May, and for this reason the idea of cleaning them was first considered in the late 1990s. Eliminating dirt and yellowed varnish is a process comparable to tuning a musical instrument and the result facilitates communication between artist and viewer.
The yellowed varnishes have been removed in both works using a cleaning process that has revealed the depth and profundity of the original colours. In addition, it is now possible to see technical details and brushstrokes that were hidden by the old varnish. The paintings were created as a pair and in their newly cleaned state it is possible to appreciate more easily the elements that relate them. The colours have regained their former depth and intensity, the figures are now in their appropriate locations and above all, the full importance of the light and its nuances is now evident.
Apart from the damage that occurred during the Civil War, the present state of the paintings is exceptionally good. Close inspection of the works reveals the outstandingly well conserved pigment, and the quality and variety of the tones in any small area chosen at random. If we also bear in mind the size of the canvases and the fact that they are a pair, it is possible to fully appreciate their exceptional nature. When the decision was taken to restore these outstandingly important paintings, it was unanimously decided in the Museum that the so-called “neutral” tints could not be retained as they significantly interfered with a correct reading of The 2nd of May in a variety of ways. The original lost paint surface, covered with a reddish tone in the 1941 restoration, displaced the viewer’s gaze from the warm original colours (the red breeches of the Mamelukes) towards the left of the composition. In addition, our gaze was lost in the area of red paint in the area originally occupied by the curved sabre, deliberately painted in that spot by Goya in order to close that corner of the composition and return the viewer’s gaze to the centre of the canvas.