LONDON.- At first glance, a 17th-century Dutch painting in the Royal Collection of a group of inanimate objects appears to be a typical still life of the period. However, recent conservation work on A Vanitas by Pieter Gerritsz. van Roestraten (c.1630–1700) has uncovered a new element to the picture – the artist's self-portrait.

The conservation treatment was undertaken in preparation for the first-ever exhibition of portraits of artists in the Royal Collection. A Vanitas (c.1666–1700) by Roestraten is one of 150 works that will go on display at The Queen's Gallery, Buckingham Palace next month in the exhibition Portrait of the Artist (from 4 November).

A 'vanitas' painting was a type of still life that conveyed a message about the misguided pursuit of transient earthly pleasures and was particularly popular in the Netherlands during the 17th century. This example by Roestraten shows a number of objects displayed on a chest – coins and a silver pocket-watch on a silk ribbon suggest the coveting of worldly possessions, a glass sphere suspended from above signifies the fragility of life, while a human skull serves as a reminder of the inevitability of death. A book is open at a print of a laughing Democritus, the Greek philosopher, which is inscribed with the lines ‘Everyone is sick from birth / vanity is ruining the world’.

During the removal of discoloured varnish, Royal Collection Trust conservators found the 3cm-high image of the artist at his easel painted as a reflection on the glass sphere. Roestraten can be seen in the surroundings of his studio, looking directly at the viewer and towards the skull and silver ginger jar in the foreground of the picture.

A pupil of the great portrait painter Frans Hals, Roestraten established himself as a still-life artist in London, where he is recorded as having been injured in the Great Fire. Best known for his pictures of luxury objects, he clearly enjoyed challenging the viewer to discover a concealed element in his work, as reflected self-portraits have been identified in at least nine of his still-life paintings.

Anna Reynolds, Senior Curator of Paintings, Royal Collection Trust, and co-curator of the exhibition, said, 'Vanitas paintings traditionally focus on symbolic objects that are designed to make us think about how we live our lives. The discovery of Roestraten's reflection, previously hidden beneath a layer of varnish, is very exciting and adds a new element to the work – a sort of pictorial game that encourages us to look more closely.'

The practice of artists incorporating their own image into their work through such subtle means or by casting themselves as characters in biblical and historical narratives is not uncommon. In Sebastiano Ricci's Christ Among the Doctors in the Temple (c.1711–16) the artist appears in the role of a doctor holding a magnifying glass, while in Judith with the Head of Holofernes (1613), the painter Cristofano Allori plays a central part in the narrative as the decapitated Holofernes.

Portrait of the Artist examines the changing image of the creative genius through more than 150 paintings, drawings, prints, photographs and decorative arts from the Royal Collection. The exhibition brings together some of the best-known images of artists, including self-portraits by Artemisia Gentileschi and Sir Peter Paul Rubens, and Francesco Melzi's chalk drawing of his teacher Leonardo da Vinci.