Why have my white blinds turned yellow on the sunny side?

Yellowing and fading are two different problems

White PVC and faux wood slats yellow. UV degrades the stabilisers in the plastic, and the surface takes on a cream or beige cast that goes right into the material rather than sitting on it. It is usually worst on the side facing the glass, which is why the blind can look fine from inside the room until you tilt it.

Dyed fabrics fade instead. The pigment breaks down and the colour lightens, often unevenly, with sharp lines where a piece of furniture or a window bar shaded part of the blind. Strong colours show it earliest, particularly reds and deep blues.

Why one blind goes and its neighbour does not

Exposure is not evenly shared in a house. A south or west facing window can receive several times the UV dose of a north facing one over a year, and coastal light in Kent is brighter than many people expect thanks to reflection off the water and open sky.

Glazing matters too. Some modern units include a low emissivity or solar control coating that cuts UV significantly, so blinds behind older glass age faster even on the same elevation of the same house.

• South and west elevations discolour first, sometimes years earlier.
• Coastal and open aspect rooms take more reflected light.
• Older glazing without a solar coating passes more UV to the blind.

Can it be reversed?

Honestly, no. Cleaning removes anything sitting on the surface, which is worth doing to rule out grime, but the yellowing itself is a change in the material and will not come back out. Household bleaches and abrasives make matters worse by dulling the surface, and on fabric they weaken the weave.

There is one thing worth doing before you accept it. Wipe a small area of a slat, let it dry and compare it with an unwiped area next to it. If it looks the same, it is UV and no cleaning regime will change that.

Materials that hold their colour

Aluminium venetian slats do not yellow, because the colour is in a baked finish rather than a plasticiser. Solution dyed and UV stabilised roller fabrics hold their tone far longer than standard dyed fabrics. Painted timber shutters in a quality finish also hold up well, which is part of why they suit big sunny rooms.

Where a room takes punishing afternoon sun, a solar or screen fabric is often the better answer altogether. It is designed to sit in that light, cuts the glare and heat you are getting anyway, and does not depend on staying bright white to look right.

• Aluminium slats: no yellowing, colour is in the finish.
• UV stabilised and solution dyed roller fabrics: much slower fading.
• Solar and screen fabrics: designed for high exposure windows.
• Painted shutters: hold colour well in bright rooms.

Getting the sunny side right next time

When we measure a house we look at which way each window faces before recommending a fabric, because specifying the same product on every elevation is how you end up with mismatched blinds in three years. It costs nothing extra to make a better choice at order stage.

We have been fitting in East Kent since 2006, with a showroom on Hythe High Street where you can see sun facing fabrics in daylight rather than under shop lighting. Every product carries its guarantee, and selected shutter ranges come with a lifetime product guarantee.