Silverpoint is
a.
a technique using the blackish residue of impure carbon obtained by removing water from animal and vegetation substances.
b.
a technique involving the use of a metal point, and a thin silver wire, popular in the 14th and 15th centuries.
c.
a printmaking technique born from crayon manner that imitates the appearance of chalk lines.
d.
a technique used since the 16th century involving a stick filled with either colored or black graphite, a heated mixture of carbon and clay.