This is original art for the cover of The Wizard of Op (1975). Ed created these eye-watering pieces of Op art using Rubylith film. Rubylith was red film attached to a clear backing film. You cut shapes on to it using a scalpel and peeled away the pieces you didn’t want. It was usually used for colour overlays but Ed used it here in order to achieve razor-sharp lines, rather than draw the piece with a radiograph pen which wasn’t giving him exactly the control he wanted. He has drawn the central section with a pen. The image was printed in black.