IPC-4101D-WAM1 covers the requirements for base materials that are referred to as laminate or prepreg. These are to be used primarily for rigid and multilayer printed boards for electrical and electronic circuits. This document contains 65 individual specification sheets that can be searched using keywords. These keywords allow the document's user to find materials of a similar nature, but with specific differing properties that fine-tune their laminate and/or prepreg selection needs. The D revision with Amendment 1 includes seven new specification sheets which reflect the expanded offerings for current commercially available laminates and prepregs with improved or additional properties that include one or more of the following: low-halogen content, high-thermal performance, high speed/high frequency performance and thermal conductivity. Additionally, to keep this revision D current with the global industry, the Amendment 1 has been added to this standard that permits laminate substitutions for four key specification sheets commonly used in the industry. Also, eight specification sheets in the prior revision were removed in this standard's D revision as they are no longer utilized nor manufactured.