  The in-plane static screening of the field originated by a charge placed in a
graphene sheet is investigated. A self-consistent field equation in the real
space domain is obtained by using a suitable Thomas-Fermi procedure. Exact and
approximated (for qualitative considerations) solutions are presented. In the
case of a charged sheet, the screened potential presents a tail dependent on
the free carrier density whose importance is connected with the local features
of the impurity system. Early conclusions about Thomas-Fermi screening in
graphene are revised.
