All around the world, the things that need to be clearly visible tend to be made of a material that is reflective. Take high visibility vests as an example of reflective clothing. High visibility vests or 'hi-vis' vests are a piece of clothing which reflect light and are worn by many road users or builders for one main reason, and that is to be clearly visible.
Being reflective is essential for anything that needs to catch the human eye and be seen easily. The same goes for number plates, as many countries have number plates that are reflective. The number plates around the world are made of reflective materials, be it metal or acrylic. These materials then have text engraved or printed which is of flat colour to ensure only the backing of the materials reflects, which makes the text on the number plates clearly visible by any road user, and most of all to authorities who need to make use of the information they see with ease.
There are many objects in day to day life that are made of reflective materials such as signs on public roads and road markings that reflect light in the event of power cuts to guide road users to stay in lane.