The fan charts are created as mega-pixel PDF files. You can view them in most any PDF viewing program, then use that program to zoom in or out as you wish. When you zoom in, you see the details in great clarity.
Details, and some examples, may be found at the Millisecond Publishing Company's web site at http://www.familyforest.com. You can also find some additional information at http://familyforest.wordpress.com/2009/10/13/.