The UNIVERSAL™ endsheet consists of two sheets of LBS endleaf held together with a reinforcing material which allows the material and endsheets to be applied at the same time. UNIVERSAL endsheets are designed to run in the cover feeder of a perfect binder without concern about the book block thickness because one gap size between the two sheets of endleaf will fit a large range of book thicknesses. Stretch reinforcing materials may be used for rounding and backing.