Carlo Crivelli

Carlo Crivelli (c. 1430 - 1495) was an Italian renaissance painter who favoured a Gothic decorative approach. Crivelli learnt his particular approach to painting in Venice and Padua, but his biography is still debated. Crivelli chose to paint in tempera only, even with the increased popularity of oil during his career.

In The Dead Christ Supported by Two Angels (c. 1470-5), along with other panels by Crivelli, the gilded background and its decoratively punched design is a sign of the artist finding influence in the late medieval tradition. However, Crivelli combines these techniques with a realistic approach to the suffering of Christ, evident in the Graphic rendering of His wounds, and the differentiation between the flesh of Christ and that of the angels. With this in mind, it is important to remember that these aesthetic choices may have been placed upon the artist by the requests of the patron. 

This image combines a section of The Dead Christ by Crivelli alongside the corresponding photograph of the painting under ultra-violet illumination. The illumination reveals the areas of the painting which contain original varnish. 

In the ultra-violet image, the areas where the original varnish remains in tact show up in fluorescence, most prominently the head of the angel. It is in these areas that the paint is immaculately preserved and the colour unfaded. For this and other reasons, the National Gallery supposed that this was the first varnish to be applied to the painting, possibly in the 15th century. 

This means that the greenish tint of Christ's skin was an aesthetic choice by Crivelli, to furhter describe the death of Christ, and hadn't changed over time.