Gág used ink to draw outlines of cats and characters, as well as for shading and creating tonal qualities. She wrote: “I aim to make the illustrations for children’s books as much a work of art as anything I would send to an art exhibition. I strive to make them completely accurate in relation to the text. I try to make them warmly human, imaginative, or humourous — not coldly decorative — and to make them so clear that a 3-year-old can recognize the main object in them.”

