If you have had an idea for designing something, you know that your ideas, thoughts and plans can come to you at odd times and in unusual places. Writing these things down in a variety of places could prove to be problematic if you ever choose to move beyond the idea phase. Very seldom does an idea drawn on a napkin, as were some of Michelangelo’s sketches for the Sistine Chapel, work as an efficient method of record keeping. That is why engineering notebooks were invented. A design or engineering notebook lets the inventor keep a written record of the design project from concept to completion. As the project progresses, research, observations, sketches and questions that arise can be recorded in the notebook, making it easy to go back and find these details later. By keeping everything in one place, recorded in neat, chronological order, you or a contemporary can go back and retrace the design process and get the same results or find the errors. If you are not sure what to put in the design notebook, include everything. It should begin the moment you first conceive of your idea and record every step, thought or idea that occurs from then on. In some instances you may need to attach other documents and drawings by means of tape or glue. As long as all the background research, interviews with experts and potential consumers, drawings and photos end up in the book, it will form a complete record of the design process. This is what engineering notebooks were meant to accomplish.