The Abhorsen series is a wildly successful line of books written by Garth Nix. Throughout the years the covers have been changed, but the brand itself has never gotten any expansion in the way of official merchandise or special editions.
The Abhorsen Trilogy
I used a three-part process for the illustrations. First, paint the basic shapes in gouache on cardboard or white board. Second, upload the base colors into photoshop and use organic shapes and textures, such as feathers, cement and tree bark, to create visual effects mimicking fabric and chain mail. Lastly, merge all elements together into a finished illustration!