Here’s another rare gem that I managed to find. Signet Signal Symbol, by Walter J. Diethelm and published in 1984, is a book displaying commercial and cultural signs, symbols, logos and icons. What makes this book very unique are the three translucent pages featuring actual design sketches from the designers. An excellent insight into the process and evolution of the designs. Book itself is pretty rare but it makes an great inspirational tool for I need to sign logos and icons.