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Start with the paint, not the brush

It is tempting to grab whatever brush is nearest when a tin of paint appears, but the tool you choose has as much influence on the finish as the paint itself. The single most useful rule to remember is this: water-based paints and solvent-based paints behave completely differently, and they demand different bristles and different roller sleeves. Get that match right and you will spend less time fighting brush marks and more time admiring a flat, even finish.

Before you buy anything, read the tin. Look for whether it is water-based (most modern emulsions, many satinwoods and eggshells, and virtually all wall and ceiling paints) or solvent-based (traditional gloss, some undercoats, wood stains and metal paints). That one detail tells you nearly everything about which brush and sleeve to reach for.

Natural bristle versus synthetic

Natural bristle brushes are usually made from hog hair. Each hair has a split, tapered end — known as a flag — that holds paint beautifully and releases it smoothly as you draw the brush along. That is why natural bristle is the traditional choice for solvent-based gloss and undercoat: it lays the paint off with long, even strokes and helps smooth out the visible brush marks that gloss is prone to showing.

The catch is water. Natural bristle absorbs moisture, so it swells, turns floppy and loses its shape when used with water-based paints. It can also be left feeling permanently fuzzy. For anything water-based, choose synthetic bristle — polyester, nylon or a blend of the two. Good synthetics are tapered and flagged to mimic the performance of hog hair, but they shrug off water, hold their spring and clean up with warm soapy water in minutes.

A simple rule of thumb:

• Water-based emulsion, satinwood, eggshell, primer: synthetic bristle.
• Solvent-based gloss, undercoat, varnish, wood stain: natural bristle, or a quality synthetic that is marked as suitable for solvent-based paints.
• If you only want one set of brushes, buy synthetic — it is the better all-rounder, though it may soften slightly after repeated contact with white spirit.

Which brush shape for which job

Size and shape matter as much as the bristle. A brush that is too wide for the job will slap paint where you do not want it; one that is too small will leave you chasing a wet edge that dries before you reach it.

• 50mm (2in) angled sash brush — the workhorse for cutting in along ceilings, skirting boards and around window frames. The angled tip gives you control at the edge.
• 25–38mm (1–1.5in) brush — ideal for narrow mouldings, door panels, window glazing bars and touching in.
• 75mm (3in) brush — good for wide, flat woodwork such as door stiles, skirting and panelling, and for laying off paint applied by roller.
• 100mm (4in) brush — best kept for large flat timber, fences and sheds where speed matters more than precision.

Whatever the size, buy the best you can afford. A cheap brush sheds hairs into the paint and leaves a scratchy finish that no amount of sanding will forgive.

Getting the roller sleeve right

Roller sleeves are described by their pile (or nap) length, and that measurement does more for your finish than the colour of the handle. Shorter pile leaves a smoother surface but carries less paint; longer pile holds more and gets into texture.

• Short pile, 4–6mm — smooth walls and ceilings, gloss and satinwood on flat doors, and anywhere a flawless finish is the goal.
• Medium pile, 8–12mm — the default for most interior emulsion on lightly textured or previously painted walls. A good all-rounder.
• Long pile, 15–20mm — heavily textured surfaces, Artex, render, brick and masonry paint.
• Foam — very smooth, low-texture surfaces such as doors and metalwork, though it holds little paint and can trap air bubbles if you over-roll.

Sleeve fabric matters too. Woven polyester and microfibre are superb with water-based paints and resist matting. Lambswool is the traditional choice for solvent-based paint, holding plenty of product and laying it off evenly, but it must be cleaned thoroughly with white spirit.

Matching sleeves to paints and surfaces

For water-based emulsion on walls, a medium-pile microfibre or woven polyester sleeve is hard to beat: it loads well, releases evenly and rinses clean. Use a 230mm (9in) sleeve for walls and a 100mm (4in) mini roller for awkward spots and behind radiators. If you are painting a smooth new plaster finish with a durable bathroom or kitchen emulsion, drop to a short-pile sleeve for a tighter finish.

For solvent-based gloss on woodwork, use a short-pile woven sleeve or a lambswool sleeve, then lay off immediately with a natural bristle brush, drawing the full length of the panel in one continuous stroke. This is the trick that removes roller stipple and gives gloss its characteristic glass-like sheen.

Cleaning and keeping your kit

Good brushes and sleeves last years if you look after them. Water-based paints rinse out with warm water and a little washing-up liquid — work the bristles against your palm until the water runs clear, then reshape and dry them bristle-down. Solvent-based paints need white spirit or brush cleaner, followed by a wash in soapy water.

Never leave a brush standing on its bristles, and never let paint dry in the heel. A few minutes of care after each coat will save you the cost of replacing everything the next time a decorating job comes round.