Cleaning an oil painting by Bui Xuan Phai

Phố Hàng Cá (‘Fish Street’) was painted in 1962 by Bùi Xuân Phái (1920-88), a Hanoi artist who became one of Vietnam’s best-known painters for his depictions of the old streets of the city.

On this painting from Witness Collection, oil paint was applied on the textured side of a hardboard panel. This cross-hatched texture, with many small indentations, is characteristic of the reverse of many different types of hardboard panels. No preparatory ground layer was applied to the support. Instead, the artist employed a limited palette of white, red and black to paint his composition directly on the support. A thick layer of surface dirt covered the entire painting, giving it a dull grey appearance. In particular, loose dust and dirt was found to be concentrated in the indentations of the support.

The painting before dirt removal

The painting required cleaning in the form of surface dirt removal. This would once again reinstate the tonal balance and clarity of the composition. Tests were undertaken at the edge of the painting in order to determine whether the surface was sensitive to moisture. Some red and black colour fields were found to be water-sensitive. However, a technique was found which safely cleaned these areas without any pigment loss. This involved using a slightly damp Mars Staedler eraser to gently rub over the surface. The damp eraser picked up surface dirt effectively without affecting the paint layers. The depressions, or indentations, in the support were cleaned using very small cotton wool swabs lightly dampened with deionised water. To give an idea of the size of these swabs, the tip of a toothpick would have been far too large. In fact, the bamboo sticks used to make swabs were constantly sharpened to a point the size of a needle, and only a few cotton wool strands were used at a time. Although painstaking, as this had to be undertaken under the stereoscopic microscope, the resulting cleaned painting looked significantly better than it had previously. The entire cleaning procedure took well over 100 hours, which demonstrates the time-consuming nature of the work.

The painting after cleaning