Flat paint brushes

A flat paint brush has bristles held in a flat ferrule and cut straight across, so you can lay down a wide band of colour with a crisp edge in a single stroke. You use it for underpainting, larger areas and straight lines in acrylic and oil painting, and for skies and washes in watercolour. Here you’ll find classic flat paint brushes, short flats (brights), angled brushes and wide wash brushes, individually and in sets from Princeton, Da Vinci, Daler Rowney, Kreul and Royal & Langnickel. Most have synthetic bristles, with hog bristle brushes also available for thick oil and acrylic paint.

Which flat paint brush should you choose?

• Classic flat brush – longer bristles hold more paint, letting you make a long, even stroke; use the broad side to cover an area and the edge to draw a thin, straight line.
• Short flat brush (bright, shader) – shorter, firmer bristles give you control over short strokes; use it for thick paint, texture and details in oil and acrylic painting.
• Angled brush – the bristles are cut at an angle; use the tip to fill corners and narrow spaces, and the full width to create a smooth transition into shadow.
• Wide wash brush (flat wash, mottler) – plenty of soft bristles for laying in a base, painting skies and applying even watercolour washes; the size is often given as the width in inches (1/4, 1/2, 1).

Size numbers vary between brands, so when adding to your brushes, choose the same range, such as Princeton Selectartiste, Daler Rowney Graduate or Da Vinci Fit Synthetics.

Flat paint brush or round paint brush?

A flat paint brush makes marks with a straight edge, making it useful for areas of colour, edges and geometric shapes. Round paint brushes have a pointed tip and can make both thin lines and lines that vary in width, so painters usually combine both shapes. If you want several widths at once, take a look at paint brush sets; you’ll find all shapes and techniques among the painting brushes.

How do you keep a flat brush’s edge straight?

After painting, wash your brush with soap and water; for oil paint, first wipe the paint out and loosen the remaining paint in thinner. Use your fingers to reshape the wet bristles into a flat edge, then leave the brush to dry flat. If you leave a brush standing bristles down in a jar, the bristles bend sideways and will no longer return to a straight edge.