What would you do to photograph a frog in a low-light exhibit at the zoo? Use your camera's flash.
Stand back from the glass.
Increase the ISO setting.
Ask the zookeeper to increase the light.

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