I highly recommend the purchase of ANY of Mr. Budzik's books, if you are involved in any aspect of the sheet metal trades. My company is mainly into architectural sheet metal, but the methods presented in many of this authors' works are indispensable - particularly those that TEACH layout methods such as triangulation, true-length lines, etc. Where else can you get clear, concise INSTRUCTION on these topics? Unless you are attending a sheet metal workers union apprenticeship program, you can't. Your only other choice is to find someone that hopefully knows, and is capable and willing to teach you. I own several of this authors books, and find that I and my employees have made these our "go-to" books when we need to know how to properly lay out a part or shape that we normally don't do, or have never done. I also have many other books on sheet metal dating back to the 1800's, and while they are indeed wonderful and useful, most are hard for the average reader to grasp, and really pale in comparison to the practicality and usefulness of Mr. Budzik's work. The only thing that would be better than these books would be to have been a student of Mr. Budzik while he was actively teaching. The methods explained in these books result in the reader/sheet metal worker "learning a trade" from a true master, that in many parts of our country is either dying or dead. Don't hesitate... buy them now!