Army Painter Colour Primer Spray - Matt Black Undercoat
Quite simply the best Black Spray on the market. Very matt and with a superior coverage - leaving the miniatures in a perfect condition for applying coats of paints.
War and Peace Games recommendation - "Quite simply this is by far the best black undercoat/base paint on the market, I go through dozens of cans of this every year. No matter what miniature's up next on your painting deck, use this!"