In those early days of TV, the BBC reserved the new Image Orthicon cameras for the adult shows in the evenings. The daytime children's shows used the old Iconoscopes, designed twenty years earlier in the mid 1930s. These overloaded when they saw white paper, so Adrian Hill always had to remind children to send in their drawings on grey paper. If they sent the pictures in on white paper, they could not be shown as the screen would go to white-out then looked as if it was covered in black oil and the camera man would have to cover the lens for a few seconds to let it settle down. For that reason the BBC's Designs Department had to test its video recording techniques in the evenings, so it had better quality images to work on.