To create the illustrations for Elska, I found models and took pictures of them in costume. I was fortunate to find a gentleman who does Viking re-enactments, and he posed in his own garb. For the children in the book, I had costumes made. I used my neighbor's boys, and for the girl in the story, I found a girl who took lessons at an Icelandic Horse farm! The research and preparation and photo reference for these books takes almost as long as creating the illustrations.
Above is the rough sketch for a scene in the story . Note that the sketch is really pretty detailed. The art director requested that the sketches be more detailed than usual, as they planned to print a "mock-up" of the book for the sales force to show to bookstores.
And here is the final picture, which is a pencil illustration.