The most basic tools anyone needs for scrimshaw are a sharp needle
and a rag--the needle for piercing or scratching the material to
be scrimmed and the rag for rubbing away excess pigment.
Of course, you won't get the best results with only these two tools.
Other basic tools needed for serious scrimshanding include:
Sandpaper (from coarse to extra fine) and/or a buffing wheel
to smooth and polish the surface to be scrimmed. A buffing wheel
will also need buffing compound.
Tracing and sketching paper for working out your rough drafts.
A special graphite pencil for writing on glass or other highly
polished surfaces.
Fine, hardened steel needles in various thicknesses.
A pin vise to hold your needle while you work.
A sharpening stone for sharpening your needles.
A good light source that can be directed on your work as you
need it.
A sand bag, usually made out of suede leather. You hold the piece
on this as you are scrimming it. You will move the piece slightly
in different directions as you work, so that the area you are scrimming
catches your light source. This is how you "see" what
areas you have scrimmed, by catching the glare off the piece.
Magnification (a lighted magnifying lamp, jeweler's loupe, or
even a stereo microscope).
And of course, you need inks or paints (pigments).