@TheDonsieLass I would not use puddled clay, it sounds great, no plastic, no oil used, but it is very hard to get right. And the pond needs to be topped up with water at all times as when the clay dries out at the edges it can crack and the pond will lose water. For your first pond it is safest and easiest to just use either a butyl or PVC liner. Butyl liner lasts a lifetime if done properly so if you are worried about plastic it is the better option.