When I was in Middle School, my shop class had a large unit devoted to mechanical drawing / drafting with pencil and paper. It was fun but also frustrating beca

When I was in Middle School, my shop class had a large unit devoted to mechanical drawing / drafting with pencil and paper. It was fun but also frustrating because the teacher was very particular about the details. If two lines were supposed to meet at a corner, and either one of them extended a little too far, he would mark down for that. Also any erasures prevented a perfect grade. Yes this was before computer drafting was practical, at least in schools.