It is easier to stencil before
the lampshade is assembled.
If the stencil is lined up,
using a light table, the inside and outside of the shade can be stenciled
to prevent light bulb washout.
Stenciling on paper can also
be cut & pierced. A number of different stencil paints can be used.
If oil base paints are used, thin with Japan Dryer and use a dry brush
technique. The real secret to stenciling on lampshades is to be mindful
that it will be used lit and unlit. Rubber stamping is also a good decorative
technique for lampshades.