Millimeter-wave imaging may be used to assist in
the problem of wastepaper recognition during the sorting and
recycling process. Currently, there are a variety of techniques,
which are used within materials recovery facilities to sort waste
paper and card; however, improvements in sorting capability can
be realized using a multiple sensors to provide complementary
(orthogonal) data. This paper discusses the issues related to
the processes, which are currently used for sorting of recycled
wastepaper and the phenomenology for millimeter-wave imaging
of a wastepaper material. Experimental measurements and
images in the millimeter wave band are presented, which support
the proposed application.