Our smallest panel width is 200mm and the widest is 750mm With larger louvre panels we do sometimes go wider, but void the warp warranty with your permission. Generally a window looks best with 4 panels, two opening as pairs either way. A 3 window bay, however, will usually have 2 panels on the smaller side windows and 4 in the centre. All panels will open away from the middle.
There are as many exceptions as there are norms. For instance, a long window with 3 panes of glass, i.e. 1800mm wide x 1000mm high, would have 6 panels – three folding either way, or if you are only going to open them to clean the windows you could easily have just 3 panels. The Americans never open the shutters, only the louvers, so they design with large panels.
A lot of the time you will have to consider where the panels are going to fold back to and if there is enough room for this to happen. This is also true where you are fitting inside the reveal next to the window and you will not want the shutters, when open, to protrude into the room too much.
We would not recommend hanging more than 3 panels from a single batten hinged together, unless they were not going to be opened apart from window cleaning and were resting on the sill or door-step. As the maximum recommended width of our panels is 750mm, you may say that this equates to 4500mm maximum width, but it would be asking a lot of the batten to hold panels of this width and weight without sagging at a later date. So quite a lot of common sense is needed to achieve a good installation. Openings over 2200mm generally need a top track. Even if not using a top track at this width, try to use a light panel such as Cedar wood or Basswood.
For partitioning or for large windows where tracking is needed at the top to suspend the panels, you will really need an even number of panels or they will look odd and not hang from the track properly. Ideally 8 panels or 12 panels for very large openings is best, although quite often it is wise to hang even 6 panels from tracking if they are quite large. With the heavier MDF shutter this is clearly an option to be considered. We do not charge for tracking, it comes in the square metre price for the opening.
In summary, the window will normally dictate the number of panels. If the window is split into two halves you would either have 2 or 4 panels and it follows that if it is three panes, then three or six panels will suffice. The vertical dividers of the windows are where the vertical stiles of the shutters should ideally be located.