This book is particularly helpful to the sheet metal worker, apprentice, or student who is learning to make fittings. The step-by-step instructions are so complete that a person learning how to layout these fittings will have no difficulty. After following the step-by-step instructions the first few times he makes each fitting, later it will be necessary to only refer to the drawings of the patterns in order to remember how specific patterns are developed. After making the fittings several times, he will become so familiar with the ones he uses most often that he can make them without the book. This book is a convenient reference for the experienced sheet metal worker who occasionally has some difficulty with a particular fitting or pattern. The instructions for making each specific pattern can be found at a glance withouth reading through the other instructions. The person who is referring to the book as a reference frequently needs only to look at the drawings of the patterns and not go through the step-by-step instructions. He already is familiar with the basic layout procedures but might not remember how a specific pattern is developed.