The Substrait of the Mother Board

Sub straiht is the stuff that then another substance is stuck to. It's basically any base material on which processing is conducted. Can you guys think of any other terms? I couldn't come across any other uses of it, except for, like, literary and poetic uses. Oh, i love this in philosophy, the underlying characterless substance that supports attributes of material reality. O on that forwooka te space time. Yesiselik a space dive,. exactlyormitin material sis m  sot could be, for example, the base to which adhesives or tape or bondings are made. Or any underlying layer could be the sub yes.