Once it had been technically established that the additions to Philip II on Horseback were not original, it was decided to conceal them as they negatively affected a visual reading of the composition. It was decided that the most appropriate course of action would be to fold these added strips over a new stretcher of the size of Rubens’s original painting.

In order to do so, the areas where the original and additional canvases joined were cleaned, protecting the edge of Rubens’s original canvas with tapes (fig. 1). These joining zones were dampened on the reverse and the additional strips then folded over the new stretcher without affecting the original paint surface at any point. 1cm of non-original paint has been left on the front face but this is not visible to the viewer as it is behind the frame.

Although the additional, later strips at the top and bottom are no longer visible, the paint surface on them has been protected with tissue paper, attached with a thin layer of animal glue with the aim of protecting them and of guaranteeing their preservation and the reversibility of the procedure (fig. 2).

The next step was to clean the old varnish that covered the painting. It was a mastic varnish and could thus be removed with dissolvents. At this point it was possible to see the losses to the paint surface that had already been detected in the x-ray.

Old areas of filling-in (which were dark in tone) were brought up to the same colour as the new ones, which used the regattino technique in which fine parallel lines give areas of loss a sense of movement that simulates the effect produced by Rubens’ brushstrokes (fig. 3).

Having completed the re-touchings, the canvas was covered with a thin layer of varnish with sufficient penetration of the paint surface to maximise the colours’ effect of richness and moistness. Once the varnish had dried another thin layer of varnish was applied with a compressor and was then toned with a silk varnishing pad.

The restoration of the painting has allowed us to appreciate it as Rubens intended due to the fact that the procedure involved covering over later additions that detracted from the dramatic presence of the King in the composition. In addition, by removing old varnish and numerous areas of re-painting, the painting now has greater tonal coherence and has recovered the vibration of light and colour that characterise original works by this great Flemish painter (fig. 4).