Shutters are available in quite a few different composites.
They can be made entirely of high density MDF; they can be MDF with Styrene louvres, or MDF frames with hardwood shutters. There are also faux wood shutters and upvc.
These are more stable and carry better guarantees from their manufacturers.
Why the variety you may ask? Well MDF is the cheapest of the wooden type but whilst it is the most stable, it is also the heaviest, so if you add Styrene louvres that adds a little to the cost but improves the weight, whilst if you then go to hardwood shutters that adds a bit more to the cost but takes away a considerable amount of the weight of the doors.
The first picture shows a set of mdf shutters in white, whilst the second picture is of a set of "Tier on Tier" shutters in wood. you can have tier on tier in any quality at no extra cost.
Shutters are also made in a variety of louvre sizes, 63mm and 89 mm being the most popular. There are also varieties of mouldings for the frames and variations in the way that you can use them in your window.
If you don't like tilt rods showing on the front of your shutters then you can also elect to have hidden rods which add a bit to the cost, but can make your shutters look tidier.
Here are some pictures of Faux wood shutters with tilt rods. These shutters have high UV values; are available in 2 to 3 weeks and carry a 10 year guarantee.