Perfect Fit blinds are a relativley new type of blind on the market. They are a bit more expensive but they look stunning and can be fitted to just about any modern plastic double glazed windows. They don't need any fixing screws as the clips that hold them go between the glass and the rubber around the window.
They can be done in pleated, roller, or venetians which are fitted within an aluminium frame in white and 2 shades of wood effect browns which then attach to the windows with clips.
They are particularly good for the plastic doubling glazing units that open inwards. Normally these can be very difficult to have any type of blinds fitted to.