sketches of personal references used for ideas and concepts.
Traditional illustrations are drawings that are created with traditional media; pencil, paints, watercolor, ink, pastels and other materials, not using digital media.
Here is a charcoal illustration from the book ‘The art of Ray Harryhusen’. The image is of a key sequence from the film ‘War of the worlds’, you can see in this image a lot of action going on but the image does not explain any information about how this would be shot, it only gives an idea of what is going and it is very detailed compared to storyboard drawings. The image almost comes to life you can imagine it happening and what would happen next.