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)
Perhaps you are expressing a desire to get away. The presence of this color in your dream may symbolize your spiritual guide and your optimism of the future. You have clarity of mind. Alternatively, the color blue may also be a metaphor for being blue and feeling sad. If you are wearing light blue in your dream, then it symbolizes your creativity.