- 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
The two paintings of The 2nd and The 3rd of May, painted by Francisco de Goya in 1814, entered the collections of the Museo del Prado at an early date but were not exhibited together until well into the 19th century. The first to go on display was The 2nd of May, which was seen by foreign visitors in the late 1840s, followed in the 1860s by The 3rd of May. With regard to early restorations, the only information now known is that in 1883 the painter-restorer Salvador Martínez-Cubells varnished the two canvases, as he noted in his workbook still preserved in the Museum. In 1936, during the Spanish Civil War and with the aim of avoiding damage to the paintings, they were carefully packed and transported in lorries to Valencia along with numerous other masterpieces from the Museum’s collection. In March 1938 they were sent to Girona and it was during this trip that the lorry transporting them was involved in a crash while passing through the village of Benicarló. The two paintings, which were packed together, received a heavy blow that split the canvases along various horizontal lines. While both were affected it was The 2nd of May that suffered the greatest damage, and two small pieces of canvas painted with original paint and possibly in very poor condition were lost on the road. These two missing areas are on the left side of the canvas at the middle and top.
In May 1938 the paintings were re-lined in the Castillo de Peralada in Girona by Tomás Pérez and Manuel Arpe y Retamino, the liner and restorer of the Museo del Prado respectively. The process of re-lining basically consists of attaching a new canvas to the back of an old, damaged one in order to give it greater resistance and strength.
In September 1939, after the end of the War, the paintings returned to the Prado where Manuel Arpe y Retamino completed the restoration of both canvases through the process of retouching or re-integrating. This involved dissimulating the damage and splits produced during the accident and applying new pigment to the areas of losses of original paint. Arpe re-integrated the original paint over the cuts in the canvas, but for the larger missing areas he decided to use a technique known as “neutral tint”, which was common in the restoration of wall paintings. This technique is used when the restorer is faced with large areas of loss and does not know the original appearance of these areas. It consists of applying a uniform colour to the area of loss which is not excessively obtrusive and which blends with the general tonality of the work.
Following Arpe y Retamino’s restoration the resulting appearance was maintained for both paintings until the most recent restoration.