From John Bettes's portrait A Man in a Black Cap (1545, Tate N01496, Fig.1), Tate's earliest picture, to the work of artists living in the present day, Tate's is a wide-ranging collection of paintings that spans five centuries.
The materials and techniques used to make such a broad span of paintings vary enormously. Oil paint, canvas, panel, hardboard, egg tempera, glue tempera, beeswax, natural resins, modern synthetic resins, house-paint, chocolate, gold leaf and water-colour all feature in the collection.
The care and treatment of this wide diversity of paintings falls to Paintings Conservation. Here are some of the things the department does.
Technical examination and analysis of paintings has a fundamental role in developing our understanding of paintings. Through microscopic and chemical analyses conservators discovered that the background in John Bettes's painting was originally bright blue. The colour was derived from the pigment smalt, which is essentially blue glass ground up into small particles. Bound in linseed oil, however, smalt often discolours to the dark greens and browns seen in this portrait, and this change of state is not reversible. It is likely that artists in John Bettes's time did not know that this might happen.
A particularly delicate and demanding part of conserving and restoring paintings is cleaning: layers of dirt, discoloured varnish and old restorations that may be disfiguring or obscuring parts of the composition are painstakingly removed.
The dark varnish on Thomas Gainsborough's portrait Portrait of Edward Richard Gardiner (c.1760-8, Tate T00727, Fig.4) made it hard to see the wonderful silvery tones and featherlight brushwork. As the varnish was removed (Fig.2), the lively qualities of the paint handling in the painting began to emerge.
Enlarge imageSimilarly with JMW Turner's heroic landscape, The Opening of the Wallhalla (1842, Tate N00533, Fig.6), the dingy grey layer of old varnish and dirt impaired our appreciation of the painting's subtle colours, sense of space, and fine condition.
Removing deposits of dirt from unvarnished paintings can have similar positive effects, as in Gwen John's The Convalescent (1918-19, Tate N04861, Fig.8).
Enlarge imageStructural work might also be necessary if the canvas or wooden panels that support the paint surface need strengthening or have been damaged. For example, Mark Rothko's popular painting Untitled (1950-2, Tate T04148), needed treatment to remove two dents in the canvas support (Fig.10). Restoring the canvas and paint to its previous state was a slow and gradual process. Distilled water was misted onto the canvas reverse to soften the canvas fibres and plasticise the paint. Through gentle manipulation of the canvas from the reverse, using a specialised temperature controlled iron, the fabric was eased back into plane.
Finally, there are some paintings which can be conserved but not restored due to fundamental changes caused by, for example, the artist's choice of method and materials. William Hilton's Editha and the Editha and the Monks Searching for the Body of Harold (exhibited 1834,Tate N00333, Fig.12) is a case in point. As a result of the artist's technique of mixing non-drying materials into his oil paint, the top layers of paint have shrunk in relation to those underneath them, leaving wide cracks. A nineteenth-century note in the painting's file recommends that the painting be rotated 180 degrees every 6 months to allow the parts of the painting to move back to their original position. Unfortunately the problem is more complex than this would suggest, and cannot be reversed.
See John Bettes's A Man in a Black Cap 1545 in the Collection.
February 2007
Established: 1957
Conservators: 9
Technicians & administrative staff: 1
Range of activity:
Care of Tate's collection of paintings, recording their structure & condition, ensuring safe storage and display and performing necessary treatment.
Checking loans in for Tate exhibitions.
Carrying out research including the technical examination of artist's technique, methods and materials.
For living artists, acquiring information through interview and by questionnaire.
Developing treatment and conservation procedures.
