Something else the would-be potter couldn’t afford to buy was clay. But, following the example of his old mentor Isaac Button, David knew the solution – he would simply dig it up free of charge and process it himself. Geology was another passionate interest of David’s and he knew that wherever there was coal, there would be clay. Years before, so many potteries just like Isaac Button’s were set up along the coal seams that lay beneath West Yorkshire for that reason – the 250 million year-old, multi-coloured sludge that was their precious raw material was so easy to come by. The clay was good and strong, capable of standing temperatures of over 1200ºC  without distortion. All David needed was a shovel, and a lot of stamina. This is where his love affair with clay began.