This book tells that pen sketch is the first choice of many artists in drawing sketches today since it is easy to carry and save, and will not stain the picture. The pen sketch is suitable for both complicated and simple painting, which can record what you see and think, including sudden inspiration or creation sketches. With overlapping rows, pen sketch has rich expressive force and it is just like a net covering the object, which correlates and cares all sorts of modelling factors, thus beneficial for the grasp of the whole and a good choice of basic contacts.