Throughout his life, de Looper worked on an intimate scale, sketching and painting in a variety of media and filling notebooks of various sizes. Over five decades, he assembled more than 70 delightful books in a range of subjects, from figure drawings, travelogues, and whimsical figures to Japanese-inspired folding creations. First exhibited in 1989 at Jones Troyer Fitzpatrick, they were immediately admired for their spontaneity and freedom. In 1995, The Phillips Collection mounted Willem de Looper: Sketchbooks and Small paintings on Paper, the first in a series of single-gallery exhibitions to highlight contemporary art.