Good Source for Hard Copy Public Domain Clip Art

Dear Rich: My sister and I are planning on writing a small book about our mom. I plan on illustrating the book. What is a good source of clip art that I can use without worrying about copyright infringement ? I actually want a hard copy of images that I can physically cut out the old fashioned way. Wow, we love real clip art -- not that digital stuff -- and we love you for reminding us of back in the day when we used to write the Monroe County obituaries and the HOT LINE column at the Bloomington Herald-Telephone (now the Herald-Times) and where the "art" department consisted of a room with unbelievable clip art catalogs. (The Dear Rich Staff could live inside that clip-art world.) ... Right, you had a question! The short answer is that one of the best sources of hard-copy clip art is Dover Publications (and no, we're not a paid affiliate).