The $SRCAND raster operation, or ROP code for BitBlt() means to combine the bits using AND. An explanation of the other ROP code, $SRCCOPY, $SRCINVERT, $PATINVERT, and $SRCPAINT can be found in the help file under _WinAPI_BitBlt(). For transparency, the idea is to combine the bits of the to created masks using $SRCAND and $SRCPAINT. Color mask - Has black where transparency will be. All other colors remain untouched. Black/White Mask - Has white where the transparency will be, all other colo