When something is hot, it deforms more easily than when it is cold. Think, for example, of butter from the refrigerator. When something is slightly deformable we call it elastic.

Bouncing ball

Elastic things bounce back to their original shape, which is why a bouncing ball bounces. He dents first and then dips and therefore jumps up again. Warm asphalt is more elastic than cold asphalt. The asphalt must also not be too hot or it will stick.


In the early days the material used to make soccer ball covers was full grain leather. It looked nice and kept the ball’s shape well when there was no other kind of technology.

There was a big problem with using regular leather, though: when it rained, footballs became too heavy due to the water absorption characteristics of leather.

In the present day, coverings use synthetic leather which is made from PVC (Poly Vinyl Chloride) or PU (Polyurethane).