We offer 5 different slat sizes here at Plantation Shutters; 47mm, 64mm, 76mm, 89mm and 114mm. Your choice of slat size will be based on both practical and design specifications – but what exactly are the differences between them, and which is best for you and your shutters?

What are slats?

  • Also referred to as louvres, slats are the individual pieces of wood in the centre of a plantation shutter that move together on a tilt mechanism.
  • Slats are either controlled by a tilt rod, or by a patented hidden tilt mechanism which allows control of the slats without the need for this tilt rod.
  • Slats can move as one or multiple combined units depending on whether a break is desired/needed and allow shutters to be adaptable for light, privacy and temperature control.

Practical Considerations

Lets firstly take a look at the practical considerations that will come into focus when choosing your slat size. It is best to categorize these into three key areas; light coming in through the slats, light blocked out by the slats and desired closeness to the window.

Light In (Open Slats)

As may be expected, smaller slat sizes cause less light to be filtered into a room due to the increased number of slats per panel. This may be desirable or necessary depending on panel size, however larger slats requiring a smaller number per panel would be the recommended choice for increased light density.

Light Out (Closed Slats)

Design specifications for the successful movement of slats cause a minimal light bleed where direct light feeds through closed slats. This is true of all slat sizes and shutters available on the market. Many years of development has offered intelligent frame design and rebated panels ensuring that as little light enters the room as possible, however larger slats do offer less slats per panel and therefore limited opportunity for light to bleed through. If increased light blocking effect is required, we would always recommend opting for room darkening blinds for surety of room darkening.

Closeness to window

We often recommend our customers to frame their shutters as close to the window as possible where window style and panel opening allows. As such, desired closeness can have an effect on slat size decision. On some windows, when utilizing a wider slat, it can be necessary to build out the frame that the shutter sits on the prevent the slats hitting the window or handles. Differing windows can mean larger frames may look irregular, in which case we would recommend a smaller slat to prevent this necessity.


Design/ Look

Small slats (47mm)

The smallest of our slat sizes is 47mm and although rarely chosen by our customers, it does have a range of benefits. More traditional in style and best suited to small panels, this slat size was once our best seller and can provide warmth in the volume of slats per panel. We only recommend this slat size for particularly small windows or panels as many slats on a single panel risks looking very busy.

Medium slats (64mm/ 76mm)

64mm and 76mm slats are undoubtedly the most popular in our range and it’s easy to see why. Attractive for all interiors, the panels are the perfect size for most windows offering a default compromise between large and small slat sizes. The classic 64mm is a commonly used slat size for louvred shutters as well as the larger, more contemporary 76mm slat.

Big slats (89mm/ 114mm)

Our biggest slats are best suited to large windows or multiple windows in the same façade to allow for a less cluttered, minimalistic look and 89mm slats have particularly increased in popularity in recent years. The 114mm slat is rarely used in residential properties as particularly large windows are needed to proportionally suit, although countering this, restaurants and large commercial sites do favour this size. Fewer slats in a panel accommodates the greatest amount of light control in a room, however these larger gaps when opened do give more visibility so slat angle for privacy is paramount.  


Shutters are light controlling but not black out. Varying levels of light filtration between louvres, frames and panels may occur. If you are sensitive to light then you could consider our integrated room darkening blind to increase light blocking capabilities, however this is an optional extra and not necessary in most cases.

Slat sizes do not affect the price of your shutters so you can opt for any size that best suits you and your home. You can contact the team on 02088719222 to discuss your shutter design and what slat sizes would be best for you. Looking for a quote? Try out our online quote calculator or book in for a full measure appointment to receive a non-commitment cost.