Dating back hundreds of years, gouache is often seen as a more opaque alternative to watercolours. The thicker density allows for a bright and robust appearance, leading artists to infuse all manner of compositions with white gouache highlights, as well as creating work with gouache as the primary medium.
Above: a selection of artwork from different eras with white and coloured gouache
Although examples date back many hundreds of years, gouache faces many challenges in survival. From atmospheric issues to severe flaking, there are several aspects you must consider when caring for such a sensitive artwork. This article will cover the appropriate care and conservation of gouache, as well as the history and application of this unique medium.
Above: detail from Flamborough Head by Winslow Homer, 1882
What is gouache?
The word ‘gouache’ comes from the Italian ‘aguazzo’ meaning wet mud. It was French artists in 1746 that coined the now international phrase ‘gouache’ in place of the Italian reference to ‘painting a guazzo’ which had a broader meaning for watercolours. You may also come across the term ‘body colour’ which is essentially a thickened watercolour or gouache without the typical inclusion of a strong white pigment.
Above: examples of gouche in 18th century art, including a drawing by Alessandro Magnasco and portraits by Hyacinthe Rigaud and Jean-Baptiste Isabey
Whilst watercolours do have binding agents, gouache has a much higher level in its formation. As well as chalk, gouache may be mixed with gum arabic, honey and animal glue to achieve its velveteen texture. Although white gouache is often used to highlight artwork, it also comes in a variety of colours such as crimson, cobalt blue and ochre.
Unlike watercolour application which produces a translucent layer on paper, gouache is a much thicker medium due to its use of heavier binding agents. Therefore, gouache does not need to be built-up in tone and is applied in one smooth layer for an immediately, fully opaque colour.
Above: detail from The Garden Court by Edward Burne-Jones, 1870–75 in graphite and watercolour, heightened with white gouache
Gouache history and use
Like many mediums, aspects of gouache can be traced back to antiquity and some historians even link it as far back as the cave paintings of early man. They may also be found in illuminated manuscripts of the mediaeval period. However, their prominence in art history became clear during the early renaissance period. During the 15th century, gouache followed in the development of tempera paint.
Above: examples of gouache used to highlight renaissance drawings to show light and perspective
Gouache was fairly obtainable and accessible to all manner of artists, though primarily used to highlight artist’s sketches or plans in advance of large scale work. The highlight was a helpful way to determine the light and shadow of a painting of sculpture and allowed the artist to find the perfect tone or perspective for their finished composition.
Above: detail from Salome with the Head of St. John the Baptist by Albrecht Altdorfer, 1517
Gouache was a perfect medium for bright and detailed illustrative work. It is a feature of many Persian miniatures and Mughal paintings produced from the 13th to 18th centuries. Today, these artworks are best known for their smooth application of colour and for their inclusion of figures in Islamic art.
Above: pages from the Shah Jahan album of Mughal illustrations, 17th century
Their small size meant these illustrations were for personal use and therefore allowed more freedom for the artist than those composed on public walls. In Persian culture, this avoided a forbidden depiction of the human figure as a religious offence. The Mughal paintings were a continuation of this islamic art, as the Mughal emperors spread the religion through the Indian subcontinent. It was later spread to Hindu and Sikh courts.
Above: detail from an illustrative page in the ‘Davis Album’ by Muhammad Zaman, 1664–65
It was not until the late 18th century that gouache became a medium in its own right for European artists. Many famous names composed purely in gouache or combined it heavily within their watercolours, as was the case with J. M. W. Turner. The vividity of coloured gouache truly came into its own during the 19th and early 20th century when the post-impressionists began to compose early modern works. Notable gouache artists include Henri De Toulouse-Lautrec, Vasily Kandinsky and Henri Matisse.
Above: detail from a drawing of Auguste Rodin in his studio by Jean François Raffaëlli, 1889
Caring for gouache art
As it is a heavier layer than watercolour and does not sink into the paper or substrate, gouache is at high risk of lifting, cracking and flaking. This is often due to the subtle expansion and contraction of paper over time, causing the rigid gouache layer to be pushed and pulled by the softer, porous material beneath. The paper may also pull against a mount or framing adhesive as it moves, causing weakened, rippled or torn edges.
Above: detail from a 17th century drawing by Gerrit van Battem with flaking a gouache layer on the figure of the Virgin Mary
Paper moves subtly due to moisture in the atmosphere, so controlling this aspect should assist in preventing this type of damage. Humidity levels should be kept at around 50% and stable, as this ensures the paper is not too damp or too dry and unlikely to consistently contract. If the paint is already lifting or flaking away, speak to our team as soon as possible and save every flake to be re-adhered with sensitive conservation treatments.
Creased and folded paper can also create areas of loss and cracking. Never roll a gouache artwork or fold it. All paintings should be kept flat and facing upright if they are not on display. In storage, ensure they are checked regularly and housed in a stable environment.
Above: detail of a watercolour and gouache painting, acid damage and foxing on the left side of the figure
In some cases, the organic binding agents in gouache may begin to degrade or fail due to the impact of microorganisms or oxidisation. In some cases this may appear as a darkening tone. If mould or foxing occurs on the paper, this requires treatment as soon as possible to stop the spread.
Some gouache pigments may be prone to fading in sunlight or degrading due to their natural materials. To avoid UV damage, we always encourage the use of museum glazing to ensure a clear view whilst avoiding 99% of UV impact. For the pigments that naturally degrade, such as white lead carbonate which may become blackened, always ask the advice of a conservator for the most ethical approach to restoration.
Above: an example of oxidised gouache turning from white to grey
Gouache restoration
Our paper conservator can treat many issues facing gouache. If the painting is on another substrate, it may be something our easel painting conservators are more qualified to treat. We can offer advice on this once we have seen a photograph of the artwork in question.
As well as consolidating cracked and flaking gouache, our conservator can provide flattening and stabilisation treatments following damage from transit or rolling in storage. This will help the paper to survive into the future without the constant strain of past folds and creases.
Above is an 18th century drawing with severe staining and surface dirt. This was fully restored by our paper conservator and frame team.
Frame damage is often an issue for any work on paper, as past framing materials may include acidic elements that stain and degrade the paper over time. This usually shows up as a yellow or brown discolouration. You may also find marks from tape or glue. This staining, as well as marks from foxing and mould growth, can be sensitively cleansed away for a clear and safe result. Our conservator float washes paper in a solution that is tested against the sensitivity of the pigments, removing only the discolouration and not the original details.
If you have a gouache painting or drawing with gouache highlights, please reach out to us for advice and an estimate for restoration, care and protective framing.
As part of our service we offer a nationwide collection and delivery service as well as information on worldwide shipping to our studio. E-mail us via info@fineart-restoration.com or call 0207 112 7576 for more information. You can also fill out the form below.
