What goes into your housepaint?

Feel a touch of Spring in the air? Just the tiniest whiff?

As we move ever closer to Spring-cleaning time, a fresh crop of Dulux and Farrow & Ball colour charts have started to poke their heads though the snow.

But since most of us spend our lives entirely surrounded by paint (yes, it’s everywhere – your walls, your ceilings, your car…) have you ever given much thought to what’s actually in it?

[Picture: a technical discussion about paint with my staff]

The ancient Egyptians used ingredients which are far from uncommon even today. And there are really just four constituents: pigment for the colour, binder to make it stick, thinner so you can get it on your brush, and additives to do all sorts of clever things like inhibit mould, or reflect more or less light.

Pigments are usually produced by specialist manufacturers who sell them on to the paint companies. Increasingly the pigments are in the form of liquid colourants which can be added to a colourless base containing the binders and thinners.

Good quality paints have higher amounts of good quality pigments, and less ‘extenders’. You see the difference very quickly when you compare a coat of quality paint with a coat of cheap paint: it covers better, and it lasts better.

In the last ten years we’ve seen the virtual disappearance of solvents (Volatile Organic Compounds or VOCs) in paint, and everything is now water-based. Few decorators were happy about this because the water-soluble base is less suitable for a really smooth finish, although it does make the brushes easier to clean. But those clever chemists are making headway: modern water-based gloss paints have improved remarkably.

What next?

Nano-technoloty and micro-encapsulation are the next big thing. We already have self-healing paint on some cars – a scratch in the paint breaks open micro-capsules, which flow new resin and colour into the gap). Micro-encapsulated aluminium flakes are used for some exterior building finishes to give colour and protect against ultra-violet light.

Nano-technology is also coming. Nano-diamonds are now being used to make paint as hard as – well – diamonds. There are some very exciting possibilities with this – it is already used in some industrial applications, although it might be a while before you’re putting diamonds on your walls.
Otherwise, if you’re thinking about a nice make-over indoors for the Spring by London’s finest painters and decorators, I will be more than happy to get a man over to you now for an estimate.

Best regards,

Geoff Parvin