We always kept any left-over paint in the shed in case we needed a colour-match touch up, but that rarely happened, not because touch-ups weren’t needed, but because they always ended up looking just like that, touched-up. The reason? The original had faded, or had yellowed and didn’t match any more, or the paint we had saved had a hardened ‘skin’ on top, which rendered it useless. So it was likely the whole room got a paint job.

But when you go to buy paint, do you know what you are buying and applying? Do you know the difference between the €7 a-gallon paint and the €35 a-gallon paint? Latex or oil based? What about the final finish?

So firstly, looking at what is paint made out of will help. It’s a mix of four basic ingredients: pigments, resins, solvents, and additives.

Pigment is the colour, and resin is the binder, or glue. Solvent is the carrier that makes it all liquid and evaporates as the paint dries.

Additives provide specific performance characteristics, such as stain-blocking or mold-killing properties.

Cheap paints have a higher percentage of solvents than better paint, and there can be up to 50 percent less pigment and resin in a gallon of cheap paint. This means that most of what you are applying with cheap paint is solvent (water or mineral spirits), which just evaporates, leaving little pigment behind, so several coats are needed just to get decent coverage. So buy the best paint you can afford, to avoid having to paint more than twice. Look for manufacturers with a good reputation, and check the label, looking for products containing about 45 percent pigment and resins per volume.

Next choice: water-based or oil-based?

All paints basically fall into two solvent categories that define their type: water-based or oil-based.

Water-based paint has water as a solvent, and is most commonly called latex (even though it doesn’t contain latex!). Many water-based paints are made with acrylic and may be called “acrylic latex.” The label “oil-based paint” is equally confusing, because it isn’t actually made with oil; it has a solvent of mineral spirits (also known as paint thinner) or alkyd resin.

Water-based (latex) paint is the most common type of paint for home use for several reasons, it cleans up with soap and water, it typically contains fewer VOCs - volatile organic compounds (gases and pollutants), is fast drying, it remains flexible, withstands movement and can prevent mildew and moisture. You can use water-based paint in almost any application in the home, from exteriors and trim to interior walls and even woodwork.

Oil-based paints are typically slower to apply, as the paint has a stickier and thicker feel to it, and can take 2-3 days to ‘cure’. During the painting process, oil-based paints are responsible for the emission of high VOCs, which creates that strong “new paint smell”. They are good for outside walls, as they are more tolerant to differing weather conditions. However, as the paint dries harder there is not a lot of flexibility within the paint, which means oil-based paints are more likely to crack, become dry, brittle, chalky or yellowy over time.

Oil-based paints require turps or other specialty thinners to be used in the clean-up process.

Next choice: Paint Sheen! There are four basic paint sheens available:

Flat paint has the least amount of sheen. This hides imperfections well and the surface creates very little glare, but it is not very washable - if you rub the surface with a damp sponge, the paint may come off on the sponge. Eggshell or Satin– these have a moderate amount of sheen and hide imperfections somewhat and produce relatively little glare. They are also fairly washable. Good for everywhere except kitchens and bathrooms. Satin is perhaps a half-step up in glossiness. Semi-gloss.

This is for kitchens, bathrooms, laundry rooms, and similar areas that need high washability and moisture-resistance. It’s okay to use eggshell or satin in these areas, too, provided the surfaces stay dry, but semi-gloss is a better all-around option. Lastly is Gloss paint. Good for use on trim, doors and cabinets because it’s tough and highly washable.

So, you are all set – you need only a roller and some good brushes, again get the best you can afford as cheap brushes will lose bristles and you will find them stuck to your newly painted wall. If you look after your brushes by washing them thoroughly after use, they will probably outlive you!