Pin-Up Girls is a grayscale adult coloring book by designer Karlon Douglas and is unlike any grayscale coloring book you have seen before! It is loaded with 18 beautiful mid tone grayscale photographs for you to color and to help aid in your creativity you also get the same 18 photographs presented in full color. These photographs are on double-sided pages, vary in levels of difficulty, and are designed with added highlights and shadows to provide you with a more realistic finished picture.