Modelling Still Life and Natural Forms
Senior 1 · Fine Arts
Modelling Still Life and Natural Forms
Lesson 1 of 4
20 min
Pick up an avocado at the market, a gourd, or a smooth stone from a riverbed. Each is a solid form: you can turn it in your hands and see a different shape from every side. In this unit you will model forms like these in clay. A group of ordinary objects arranged so that you can study them, such as fruit, a gourd and a leaf, is called a still life. Things shaped by nature, such as seed pods, shells, roots, stones and leaves, are called natural forms. Potters in Rwanda have shaped local clay by hand for centuries, building cooking pots (inkono) and water jars (ibibindi) without a wheel. Before you can model well, you need to know how clay behaves: what you can do with it when it is soft, when it is half dry and when it is dry, and why it always gets smaller.
Rain and rivers wear rock down into tiny particles, which wash downhill and settle in valley bottoms, marshes and river banks. That is why clay is found in low, wet ground. Red and brown clays contain iron; grey clays often contain decayed plant matter. Buy clay from a potter, a brickmaker or an art supplier, or dig it only where the landowner and local leaders allow it: many of Rwanda's wetlands are protected. Clay dug from the ground must be cleaned of stones and roots before you use it.
Then knead (wedge) it for a few minutes, pushing, folding and turning it like dough, so that it is the same all through and has no air pockets.
| Stage | What it is like | What you can do |
|---|---|---|
| Plastic (soft) | Damp, bends easily, takes fingerprints | Model, add pieces, join with score and slip |
| Leather-hard | Firm like hard cheese, still cool and slightly damp | Carve fine details, smooth or polish, join only with great care |
| Bone-dry | Pale, light, fragile, no longer cool against your cheek | Nothing more; lift it with both hands. It is ready to fire |
| Fired (terracotta) | Hard; it rings when tapped | Paint or seal it. It is permanent and will not soften in water |
A model that is only air-dried stays fragile and turns back into mud if it gets wet. In this unit your models are air-dried, unless your school has a kiln and your teacher prepares them for firing.
In soft clay, thin films of water lie between the particles. As the clay dries, the water evaporates and the particles move closer together, so the whole piece gets smaller. Most clays shrink by roughly 5 to 10 per cent between soft and bone-dry, and a little more when fired. This causes two problems. First, your model ends up smaller than you planned. Second, a thin part dries and shrinks sooner than a thick part next to it, and the two pull apart: that is where cracks appear. So keep walls even, about 1 cm thick, and dry work slowly.
Umutoni wants to know how much her clay shrinks. She rolls a slab 1 cm thick, cuts a bar and scratches a line exactly 10.0 cm long. A week later the bar is bone-dry and the line measures 9.3 cm.
You need: about 2 kg of clay, a strong plastic bag, a cotton cloth, a ruler, a needle tool (a large nail pushed into a cork), two flat sticks 1 cm thick and an empty glass bottle to roll with.
In this photo a potter in Rwanda is shaping a bowl by hand. Look at the rim: it is being pressed and smoothed between the fingers and thumb, and the wall is thin and even all the way round. The clay is at the plastic stage: soft enough to keep the marks of the fingers, but firm enough to stand up. The bumps and finger marks inside will be smoothed away later.
Warning
Safety
Tip
“Fingerprint yes, sticky no.” Clay that takes a clear fingerprint without sticking is ready. Remember the stages in order: plastic, leather-hard, bone-dry, fired. And because clay shrinks, model a little bigger than you want the finished piece to be.
Name the four stages of clay in order, and give one thing you can still do at the leather-hard stage.
Solution: plastic, leather-hard, bone-dry, fired. At leather-hard you can carve fine details, smooth or polish the surface, and still join pieces with great care.
A line 10.0 cm long on a test bar measures 9.0 cm when the bar is bone-dry. What is the shrinkage?
Solution: 10.0 − 9.0 = 1.0 cm lost; 1.0 ÷ 10.0 × 100 = 10 per cent.
With the clay from question 2, how long should you model a mango that must be 18 cm long when dry?
Solution: the dry clay keeps 90 per cent of its length, so model it 18 ÷ 0.9 = 20 cm long.
Gatete's clay sticks to his fingers and his coils sag. What is wrong, and what should he do?
Solution: the clay is too wet. He should spread it on a dry cloth or dry bricks for a short time, then knead it until it takes a fingerprint without sticking.
Explain the difference between a still life and a natural form, with one example of each.
Solution: a still life is a group of objects arranged to be studied, for example a basket with two avocados; a natural form is a single thing shaped by nature, for example a seed pod or a shell.
Remember
Sources and credits
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
