I first learned about ticket rails as a teenager working in restaurants. I consider them the perfect object: Functional, minimal, and elegant in their simplicity. If you don't know what they are, they're used to hold paper tickets in restaurants. All you do is slide the ticket up into the slot, and it's held fast. You can move the ticket side-to-side or pull it back out with no damage to the paper. The body is just an aluminum extrusion, with the front face angled at the bottom. That's because inside, there are marbles or ball bearings. The angle on the face causes the marbles to press towards the back of the rail, which holds the paper in place. The contact points of the marbles on the paper provide just enough pressure. Plastic caps at the end hold the marbles in place. As an adult I bought two from a restaurant supply store. I use them in my shop, to hold plans and shop drawings. They're way faster than using tape or push pins and they don't mar the drawing.