Choosing a material
A designer asks four questions before choosing a material.
- Properties: is it strong, light, hard, flexible, waterproof?
- Cost: can people afford it, and is it easy to find?
- Look and feel: warm like wood, cool like metal, smooth like ceramic.
- Care for the earth: can it be reused or recycled?
Wood is warm and easy to work. Metal is strong and can be thin. Plastic is light, cheap and can be coloured. Ceramic is hard and heat-proof but can crack.
Processing: how a material is shaped
Processing means changing the shape of a material. The main kinds are:
- Cutting (sawing, laser cutting): take material away.
- Bending and forming: reshape without cutting. Metal tube can be bent hot or cold.
- Joining: screws, glue, welding.
- Moulding and casting: pour or press hot plastic or metal into a mould. It is fast for large numbers.
- 3D printing: build up layer by layer from a computer file.
Not every process suits every material. You cannot mould wood like plastic.
How new materials and processing widen design
When a new material or process appears, designers can make what was impossible before.
- Bent steel tube made light, strong chairs without carved wood.
- Plastic moulding made cheap, bright, one-piece objects for everyone.
- 3D printing makes complex shapes, like hollow lattices or parts fitted to one person.
- Smart and recycled materials add new properties or reduce waste.
Good designers match the material, the process and the job.
Key formulas and definitions
- Material choice = properties + cost + look + effect on the earth
- Processing = cutting, bending, joining, moulding, 3D printing
- New material or process = new shapes possible
- Best design = right material + right process + right job
Worked examples
1. A chair needs a strong, thin frame. Which material suits it better, wood or steel tube? Why?
Steel tube. It is much stronger for its thickness, so the frame can be thin and light. Wood would need to be thick.
2. A factory must make 10,000 identical plastic cups. Which process fits best?
Moulding. One mould can make thousands of identical cups quickly and cheaply.
3. A designer needs one hollow part with a complex inside, only five pieces. Which process?
3D printing. It builds the shape layer by layer, so inside shapes are no problem and no expensive mould is needed for only five pieces.
4. Why is ceramic a poor choice for a child's drop-proof lunch box?
Ceramic is hard but brittle. It cracks when dropped. Plastic or steel is tougher.
Common mistakes
- Choosing a material only for its looks and forgetting strength and cost.
- Thinking one process works for every material. Wood cannot be moulded like plastic.
- Confusing 'strong' and 'hard'. Ceramic is hard but can still break when dropped.
- Forgetting how many items are needed. Moulds are worth it for thousands, not for five.