Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Valuable Information about Scratchboard Medium

This book is awesome in not only covering the little known subject of scratchboard art; but in the quality of artwork, and the highly informative and lovely presentation. A must for anybody who loves to draw and is curious to try the new changes in scratchboard as a professional art panel. Enough info & inspiration for a long time. Good for both beginner and advanced artists.