Blu Tack is a must-have for many sticking up posters and notices to walls. How would teenagers decorate their bedrooms without it?
Billions of packets of Blu Tack have been sold over the past four decades. We know where it was invented – at a glue factory in Leicester. But no one knows exactly who the inventor was, as Aaron Heslehurst explains.
Video producer: Jeremy Howell
Source: BBC News