Techniques are provided for mounting simulated muntin bars, preassembled muntin grids and the like between parallel glazing sheets in an integrated multipane window sash. Among the mounting techniques disclosed are clips for holding simulated muntin components to a spacing and mounting structure of an integrated multipane window sash. Clip-less embodiments are also presented, as well as a one-piece sash that includes integral muntins and an integral spacing and mounting structure for the glazing sheets.
