A rain screen system for attaching an array of panels to the outside of a building, by means of a track system. The track system includes a series of horizontal mounting tracks that extend across the entire width of the panel array. Each horizontal mounting track has an upturned building-side leg that forms both a mounting flange, through a local shim, to the building, as well as the building side of a water tight, continuous, self draining gutter system. Each track also has an upturned panel-side leg that forms both a mounting flange for the lower edge of a panel and the panel side of the gutter system. Each track also forms a water seal at the top edge of the panel. The gutter system has a weep holes on the panel side of the gutter system, adapted so that drainage is fed to the top of the lower panel.