It is important to understand the difference between a textbook and electronic notes. Despite great advances of computer media a book still offers many advantages over the computer screen. I can take a book on the train, I can take it with me to study under a tree, I can use it next to a warming fire in winter. All these factors make learning from a book often more enjoyable than learning from a screen. It is therefore understandable that many students want to have their printed version of these notes.
Electronic notes have their own advantages.
They make it easy to use colour in text and illustrations which, if used properly, can be of great assistance in the learning process. They allow the use of animations which can dramatically clarify complicated issues. They can be upgraded daily in response to comments from users and developments in science. It is obvious that printing the notes will not produce a textbook but a collection of working sheets which do not contain animated information and may soon be outdated. These notes began as an electronic version of printed lecture notes in black and white.