Scratchboard is a direct engraving illustrative technique that resembles wood engravings or wood-cut prints.

A scratchboard is made with a thin layer of white kaolin clay covering a hardboard that is then coated with a thin top layer of black India ink.

Starting with an all black surface and using a sharp 'scratch' tool, the black ink is scraped away to reveal the white clay to make the illustration.  

All the images and stairsteps on the Timeline Posters were hand drawn using this engraving technique. The illustrations were then scanned into the computer and arranged into the Timeline poster design using Photoshop.