|Bou Inania Madrasa, Fes
The subject matter of Gebs follows that of Islamic decoration generally. The most widespread application is for geometric designs that are likewise found in "zellige", the coloured tile decoration. Arabic calligraphy is also a common application of chiselled gypsum plaster, either to express passages from the Qur'an or Arabic poetry. However, in comparison to wood or stone, gypsum plaster is so well adapted to be carved in organic, curvilinear forms that vegetal decoration of highly stylised scrolling vines, leaves and flowers are an almost distinguishing feature of this medium.
|Gebs in action
Mise en Œuvre
Today, as Gebs is mostly used in interiors the widely available Plaster of Paris, low fired gypsum plaster is used. However, for much of the historic work exposed to the exterior an impure gypsum was fired at higher temperatures resulting in a slower initial set but contributing greater density and resistance to efflorescence and weathering. At a minimum the plaster should be applied to a thickness of 3/4"; however, the best work will be carved deeply and may require a plaster application of up to two inches thick. Gypsum plasters have an initial set anywhere from mere minutes to a few hours. Typically, the plaster application is carried out a day before the design is transferred and the carving begins. The plaster will take a week or two depending on ambient humidity to dry fully. During this time, it is highly workable and the working time can be extended if necessary by continuing to saturate the plaster each day. The initial set renders the surface hard enough to carve while the moisture content within keeps it workable and prevents it from becoming too brittle and prone to fracture.
Designs are worked out ahead of time using compass and rule on paper. The designs are then transferred by inscribing lightly into the surface of the plaster with a set of dividers, "dabd" (دابد). Often a template is prepared to more readily convey at least some of the basic information; however, it only serves as a loose guide, most of the decisions have to be made by the artisan in the moment of carving. Similar to stone carving, a line is established from which you excavate towards, not from the line. However, the plaster chisels are hand held; there is no hammer. And unlike wood, the plaster is completely homogeneous and consistent so there is no grain to consider. As a result, there is markedly more control and nuance that can be achieved in carving plaster than these other materials. Another advantage is that if minor mistakes are made, gypsum plaster is a material that can be "pointed", that is to say touched up readily. A little careful sanding here and there after the plaster has fully dried can also remove textural imperfections. Customarily, a couple of coats of a clay wash are applied to antique the surface without sealing it.
The chisels, nqash (نقاش), needed are simple but specific. They are thin, relatively long and come in various widths of high carbon forged steel. It is critically important that the heads are rectangular and that the shafts do not taper. The chisels can be used alternatively to gouge, cut like a knife, or smooth like a small spatula. Although work can be done as panels in a studio for affixing on site, the best and most enduring work is done in-situ.
Essentially Gebs is bas-relief work using gypsum plaster as a medium. Thus, many of these principles are generally applicable to relief work whereas a few are very specific or characteristic of Gebs. Contrast is obviously a basic principle shared across many mediums: large/small motifs, straight/curved elements, smooth/textured surfaces. Closely related to this is depth; shallow chiselled surface will read lighter whereas deeply carved surfaces will result in dramatic shadow. This interplay of light and shadow is critical to reading the design.
|The Nasrid Palace, La Alhambra
Almost 20 years ago, I first came to Marrakech to study another Moroccan plaster tradition, Tadelakt. I was completely seduced and overwhelmed by the Gebs designs I saw at that time, never imagining that I would have opportunity to learn this craft. However, since that time I’ve completed an apprenticeship in stone carving and spent many years studying Islamic design that have prepared me for this moment. Presently, we’re in discussions with artisans in Granada, Spain and Fes, Morocco about conducting workshops and diffusing this incredible art further afield.
Contributed by Patrick Webb