Rosalind E. Krauss at Artforum:
In contrast with this array of translucence, viscosity, gleam, Johns exploits the matte, the opaque, the alkaline. His wax encaustic, charcoal, grease, paint stick all militate—it would seem—against sheen.
But that is to overlook the glassy gleam of the mirror, which holds the represented object apart from its suspended reflection on the surface of representation. When Johns worked with Samuel Beckett on the 1976 book Foirades/Fizzles, Johns refused to illustrate a well-known work, such as the suggested Waiting for Godot, instead requesting a new text. (Beckett responded, “A new work? You mean you want me to write another book?”) Beckett ultimately sent Johns five unpublished fragments, for which the artist created etchings of crosshatchings that serve as reinforcements of the planar surface of the page. Beckett chose these for the endpapers of the book, and Johns responded with the (inevitable) painting End Paper, 1976.
more here.