Apologies in advance but I have to nerd out now. Many years ago I built a model railway for a competition. In the centre was a water powered mill. It was just going to be a plain water mill but I did some research on mills and just had to make it a fulling mill. Fulling mills hammered felt to make cloth which was then soaked in urine to give it strength (later they used fullercite because - well it's wee.) and to dry the cloth they had a rack outside called a tenter rack. The rack had hooks on it to stretch the cloth and when the cloth dried it shrank and went taught. And this is where the expression on tenter hooks actually comes from.
So.. I'm excited to find out whats next with Perch! (...I'm not sat here soaked in widdle getting stressed.)
Fascinating! Did you win the competition by the way?