A brush is a simple thing: hairs, a metal ferrule, a handle. Yet the shape of those hairs decides whether you can lay a crisp edge, blend a soft cheek or flick a single blade of grass. Beginners often buy a big multipack, then wonder why nothing behaves the way they hoped. The answer is rarely more brushes — it's the right few. Once you know what each shape does and what the bristles are made of, choosing gets quick and looking after them becomes obvious.
Start With Shape, Not Brand
Four shapes cover almost everything a beginner wants to do. Learn them and you can walk past the bargain bundles with a clear head.
Round
The workhorse. A round brush has a pointed tip and a fat belly, so it holds a useful reservoir of paint or water and still finishes a line cleanly. Rounds handle thin lines, thick strokes, dots, swirls and lettering. Hold the brush upright near the ferrule for detail; press down for a wider mark. If you buy only one brush, make it a round in roughly size 6 to 8, plus a size 2 for small work.
Flat
A flat has a squared end and straight sides. Load the edge for a crisp line, drag the flat face for blocks of colour, or turn it on its corner for thin strokes. Flats suit oils and acrylics, where bold marks and clean edges are welcome, and they are excellent for dry-brush texture. Sizes usually refer to the width of the head in millimetres or inches.
Filbert
A filbert is a flat with a rounded tip — an almond shape that behaves like a softer, more forgiving flat. It lays down colour quickly but leaves no hard edge, which makes it ideal for petals, leaves, clouds and soft blending. If crisp edges are tricky for you, a filbert will flatter you.
Fan
Fan brushes spread their hairs like a hand of cards. They are texture tools rather than drawing tools: grass, foliage, fur, ripples in water, streaky dry-brush effects. Used almost dry, a fan also softens an edge beautifully. Splayed hairs are hard to restore, so don't scrub with one.
Bristles: Natural, Synthetic and Blends
Hair type matters as much as shape, because it decides how much paint the brush holds, how springy it feels and which mediums it can survive.
Natural hair comes in several characters. Hog bristle is stiff and split at the tip, which makes it ideal for pushing thick oil paint around and leaving visible brushmarks. Sable is soft, springy and tapered, holding a fine point and plenty of water — the classic watercolour brush, and the most expensive. Squirrel and similar soft hairs hold water generously but have little snap, so they suit washes rather than precision.
Synthetic filaments — usually polyester or nylon, often sold as taklon — are made to imitate those qualities. They keep a sharp point, don't shed, and behave consistently from brush to brush. They are the sensible choice for acrylics, which dry into a hard film that ruins natural hair, and modern synthetics are more than good enough for watercolour. Blends mix the two, giving a synthetic brush a little more softness and water retention.
A rough guide to matching brush to medium:
- Watercolour: soft synthetic or sable, with a fine point and a good belly.
- Acrylics: stiff synthetic, kept separate from every other medium.
- Oils: hog bristle for texture, synthetic for fine detail.
- Ink, gouache and craft paint: firm synthetic rounds and flats.
Once a brush has met acrylic or oil paint, retire it to that medium. Traces left deep in the ferrule will contaminate a delicate watercolour wash.
How to Clean Brushes Properly
Most brushes die of neglect rather than use. Five minutes at the end of a session keeps a good brush going for years.
- Wipe first. Draw the brush across a rag or kitchen paper to lift excess paint. Don't push the hairs down into the ferrule — that's where paint gathers and sets hard.
- Rinse in the right liquid. Watercolour and gouache need only lukewarm water. Acrylics need rinsing before they dry. Oils need white spirit or brush cleaner first, then soap. Lukewarm, not hot: hot water softens the glue holding the ferrule.
- Wash with mild soap. A bar of plain soap or a proper brush soap works well. Lather it in the palm of your hand, rinse, and repeat until the water runs clear and no colour comes out.
- Reshape and dry. Draw the hairs back into their natural point with your fingers and lay the brush flat, or stand it handle-down with the bristles clear of everything. A trace of soap helps hold the shape if the brush is going away for a while.
Never leave a brush standing in a jar of water. Water creeps past the ferrule, swells the handle and loosens the glue, and the hairs curl into a permanent bend. Solvents such as white spirit and turpentine give off fumes, so work near an open window and follow the safety guidance on the tin. If you have a respiratory condition or are pregnant, speak to your GP before using them regularly.
