Art Books Published   In the spring of 1955, Reinhold Publishing Corporation commissioned Leonard to write a book on the techniques and challenges of watercolors for the professional and advanced painter, hence “Watercolor: A Challenge”.  The book was so successful, he subsequently was commissioned to write a series of seven more books on painting.  All of the books are out of print but can be found by searching rare and used books stores on the internet.         Watercolor: A Challenge, 1957 Library of Congress Catalog Card Number: 57-6540             Oil Painting: Traditional and New, 1959 Library of Congress Catalog Card Number: 59-11376             Course in Wash Drawing, 1961 Library of Congress Catalog Card Number: 61-10717             Course in Casein Painting, 1961 Library of Congress Catalog Card Number: 61-10718             Painting and Understanding Abstract Art, 1964 Library of Congress Catalog Card Number: 64-22421             Painter’s Workshop, 1969 Library of Congress Catalog Card Number: 69-16382             Oil Painting: Basic and New Techniques, 1971 Library of Congress Catalog Card Number: 70-146182             The Many Ways of Water and Color, 1977