3D

3D 16-11

Today we learned plaster casting techniques and produced both a mould from damp clay and a then a solid piece of work made from plaster.

Plaster is made from powdered gypsum, which when mixed with water becomes thick like liquid cement, and creates an exothermic reaction as it hardens over a period of 15-20 minutes. Plaster remains relatively soft compared to concrete or similar mixtures, and so it can be filed down or have sand paper applied to it once it has hardened, which makes it ideal for artistic uses. Plaster must be treated with care as injury can occur if hands or fingers are left inside plaster as it is hardening – the exothermic reaction resulting in severe burns.

The clay mould also has to be strong enough to withstand the fairly considerable weight of the plaster in it's liquid state. The mould requires that containing barriers are in place as per the design, to contain the plaster as well as shape it. Most of the work produced today had leaks occur due to weaknesses in the mould, typically on joining edges, and hastily prepared reinforcements were needed to secure these weak points as plaster began to leak or spill out. Care has to be taken also to prevent air bubbles that can occur as the plaster is poured into the mould – banging on the surface of the work area can collapse some bubbles, but this is not necessarily wise depending on the fragility of the mould. Alternatively, the plaster can be upset gently by hands being applied to the surface, upsetting the contents, though again care must be taken to prevent damage to the mould and to prevent injury.

My mould leaked from several small points around the edges of joins, and the weight of the plaster was beginning to push the sides of the mould outwards, so string was used to reinforce the sides.

My mould was somewhat ambitious in terms of intricate, small areas, which turned out to be a bad idea as removing clay from the plaster cast proved to be quite difficult and required a lot of effort. Applying water to some of these 'tunnels' helped to a degree, to soften the clay and make it easier to manipulate, but this took some time and was not totally successful on the day. Working with plaster requires an understanding of negative space, as the plaster fills empty space to create solid space, so the mould design is inverse to what our expectations would be of the final piece. With practise, plaster casting can result in quite dramatic results, and the piece I produced, though largely just an exercise in the medium, has some interesting features that were good for photography. My main concept when designing the mould was landscapes, and was partially influenced by H.R Giger's landscape designs for the film Alien, as see in his 'Giger's Alien' book, which I have had since a child and have long held a fascination for. The otherworldly landscapes were produced on a large scale, typically using a wooden fram base, and using combinations of large pipes, jute plaster. Giger's landscapes, both from his work on the film and in his more typical works, have always captured my imagination, and in the case of the 'Alien' designs, they definitely live up to the films' title.

Plaster cast clay mould, with too many small details to prove difficult to manage later on.

Plaster leakage meant that reinforcement was needed on the corners, and string was used to force the sides of the mould to stay together and resist the pressure of the plaster pushing them outwards.

The plaster cast after clay was removed – many interesting shapes were produced by simply pushing into the clay with a piece of word, creating regular and roughly equal sized indentations that resulted inversely in protrusions..

By linking the side and base of the mould with a thick piece of clay, inversely a tunnel was created in the mould, which although it was difficult to clear, resulted in quite an interesting effect.

The plaster, with the remnants of the clay discolouration in the fine lines, gives an impression of bone, particularly in the more rounded areas, which would be an interesting area to develop further work. The organic, fleshy or boney shapes being represented in a landscape-esque manner, combined with close-up photography, results in striking images

Images from H.R Giger's book, 'Giger's Alien', illustrating the large scale efforts on set to create the alien world. In the finished film, matte paintings were also used in post-production to flesh out the landscape well into the distance, an art form in it's right and one which has been unfortunately superceded by digital methods such as CGI, which effectively removes the painterly look of classic cinema.

Matte painting from Alien combined with model work