Thom Yorke and Stanley Donwood never worked together in an obvious way. Instead, they created a different way of thinking about creativity. Two people producing in tandem with each working concurrently and constantly bouncing images and ideas between them – pages torn from sketchbooks shared via fax (in 1999, the internet and emails were still in their infancy). Their drawings, which feed into record covers and Radiohead's expanded website and visual material, are more like diptychs than duets.TEST SPECIMENS brings together 60 works on paper Yorke and Donwood created in 1999-2001, whilst also working on the iconic turn of the millennium albums Kid A (2000) and Amnesiac (2001).