The paper will explain the concept of illustration, its history, techniques and styles. It will be explored how important the choice of technique and style of illustration to be used in a picture book is, depending on the age group for which it is intended. A picture book is an illustrated book intended for children of different ages, created with the aim of stimulating the child's development or for their entertainment. The picture book is a combination of illustration and text, and the role of the illustration is to clarify the text for us, although the story in the picture book can also be told only with illustrations. The role of illustration in a picture book will be investigated. In addition to the illustrations, other design elements that affect the aesthetics of the picture book will be explored, such as choosing the size and type of font, formatting the text, choosing colors and tones, the composition of the illustrations, the attractiveness of the cover, and the format of the picture book itself. The idea of the work is to investigate the reaction of the audience, that is, through a survey, to investigate the reactions of different age groups to certain styles of illustrations and other design elements. The obtained results will be supported by our own design. A short own picture book intended for a certain age group, adapted to the needs of the market according to the results of the survey, will be shown. The process of making it, the art techniques used and the elements found in the picture book will also be shown and explained.