No-one would sit down in a Jumbo jet with a tail stuck together using handicraft glue. On the other hand, a high-technology adhesive developed to permanently bond glass to steel would be rather overqualified for sticking together the wrapping on the Christmas presents. As well as being far too expensive.

What makes the job of an adhesives expert so tricky is that lots of things have come along since the stone age. Yet the toolbox of modern raw materials for adhesives certainly hasn’t been filled to overflowing. Only around a dozen plastics have established themselves as technically meaningful – from workhorses like polyacrylates and synthetic rubbers to exotics such as silicones and so-called polysulfides. But they all work in much the same way. “The important thing about a glue is that it sticks. It also has to demonstrate good internal strength,” says Herrmann. Specialists refer to these two vital properties as adhesion – sticking power – and cohesion – the ability to hold together. After all, what use is a material that sticks like chewing gum, but breaks in the middle as soon as it is subjected to a load? To put it another way, if you’re gluing wood, it makes sense to use an adhesive that’s stronger than rice paper.