The tools needed for glass painting are few and relatively common, although the blender is specialised. The minimum you need are:
Glass palette –
a lightly etched glass sheet on which to grind and mix the paints
Palette knife –
a paint knife with a flexible metal blade used to mix and pile the paint
Tracing brush –
a thin and long-haired brush used to apply paint to glass. Sable is considered superior as it can hold a lot of paint allowing long lines.
Badger blender –
a wide and flat brush made of badger hair used to blend or evenly disperse a layer of paint on the glass, or to stipple a fine layer for a pin-hole effect
a round, thick brush used to apply wet paint and create a stippled matte.