Apparatus for spraying liquids, and disposable containers and liners suitable for use therewith

1. A method of preparing a gravity fed liquid spraying apparatus comprising the steps of:

• a) providing a liner having a base and sidewalls, or a sidewall, and an opening and being capable of standing unsupported on the base with the side walls extended and upright;
  
  b) placing the liner in an outer container, wherein the container having a base and an open end at a top edge of the container;
  
  c) with the container standing upright on the base and the liner positioned in the container with the sidewall or sidewalls of the liner extended upward from the base of the liner, adding liquid to the liner through the opening;
  
  d) attaching to the combination of the outer container and liner a lid which covers the opening of the container and the liner and has an outlet, the combination of liner, outer container and lid comprising a reservoir;
  
  e) connecting a spray gun to the outlet of the lid;
  
  f) inverting the combination of the spray gun and reservoir so that the reservoir is above the spray gun;
  
  g) removing the liner from the outer container together with lid, wherein the lid engages the liner so that the liner can be lifted from the outer container together with the lid.