Natural materials originate from plants, animals, or geological sources and retain much of their naturally occurring structure. Human-made materials are created by deliberately transforming, combining, or synthesizing raw materials to produce desired properties.
In A3.1 Material classification and properties, the distinction depends mainly on a material's origin and the extent to which humans have altered its structure. Natural materials may still undergo processing: timber can be cut and dried, while cotton can be cleaned and spun without becoming a human-made material.
Human-made materials are produced through controlled manufacturing. Some are synthetic materials, such as nylon and acrylic, made through chemical synthesis. Others are engineered from natural raw materials, such as plywood, glass, paper, and steel.
| Classification | Defining features | Examples |
|---|---|---|
| Natural | Obtained from biological or geological sources; natural structure remains substantially recognizable | Timber, cotton, wool, leather, natural rubber |
| Human-made | Produced by significantly transforming, combining, or synthesizing raw materials | Nylon, acrylic, glass, steel, paper, plywood |
This classification affects material selection because natural and human-made materials often have different physical properties, consistency, environmental impacts, and manufacturing possibilities. Timber has natural grain and may vary between samples, whereas acrylic can be manufactured with more uniform dimensions, colour, and properties.
A common misconception is that any processed material is human-made. Processing alone does not determine the classification: sawn timber remains natural because cutting does not fundamentally create a new material. Plywood is human-made because veneers are deliberately layered and bonded to engineer different performance characteristics.
For an IB exam response, first classify the material, then justify the classification using its source and processing. If asked to compare materials, connect classification to relevant properties and design decisions rather than merely listing examples.