The materials and procedures of the 19th-century lithographer are duplicated in almost every respect by the contemporary hand printer. An image is drawn with tusche (a carbon pigment in liquid form) and litho crayon before the printing surface is fixed, moistened, and inked in preparation for printing. The printing itself is done on a press that exerts a sliding or scraping pressure.
The dream about keys is a dream that refers to solutions to one's life problems. The question you have to ask yourself when you have this type of dream is 'what is the problem I have today that needs a solution, or a key? (read all at source)
To dream of an unknown man indicates that a decision needs to be made. This dream also suggests that you need to learn something new. There is a sense of learning what areas of your life need improvement. Is it considered that a man's appearance is triggered by a sense of depression. This dream also suggests that a friend may appear in your life and be a source of inspiration.