As amendment to IPC-4101D, Specification for Base Materials for Rigid and Multilayer Printed Boards, IPC-4101D-WAM1 delivers trending information for base materials used for rigid and multilayer printed boards. This revised standard, released by IPC, also covers requirements for laminate or prepreg base materials primarily used for rigid and multilayer printed boards for electrical and electronic circuits. There are also 64 individual, keyword-searchable specification sheets and one new table.