Which Paint Brush Should You Buy? Sizes Explained

Short answer: buy three widths, not one. A 3 or 4 inch for large flat areas, a 2 inch for doors and cutting in, and a 1 inch for frames, edges and touch-ups. Trying to do everything with a single brush is the usual reason a paint job ends up looking uneven.

What each width is for

We stock Ravi (Classic, Classic Pro, Smart and Easy) and Xiao brushes across these widths, in the Paints section.

Brush or roller?

A roller covers a large flat area faster and leaves a more even film. A brush gives you the edge. Most jobs use both: brush the edges and corners first — “cutting in” — then roller the middle before the brushed edge dries, so the two blend into each other.

Match the brush to the paint

• Emulsion and water-based paints: synthetic bristles, which hold their shape in water. Wash out in water.
• Enamel, varnish and oil-based paints: natural bristle, which holds and releases oil paint better. Clean in thinner.
• Never use the same brush for both without cleaning it properly in between — traces of one will spoil the finish of the other.

Making a brush last

1. Wet the brush first — water for emulsion, thinner for enamel. Paint then washes out instead of drying into the root.
2. Do not load past a third of the bristle length. Paint pushed into the root is what makes a brush go hard.
3. Clean it immediately. A brush left overnight is usually finished.
4. Dry it hanging or flat, never standing on the bristles.
5. Wrap it in paper while it dries and it keeps its chisel edge — which is what gives you a clean line next time.

When to replace it

Splayed bristles that will not come back to a point, a hard root, or bristles shedding into the paint. A worn brush costs more in rework than a new one costs to buy.

While you are painting

If you are preparing steel — gates, grilles, railings — a wire brush and primer matter more than the paint itself; see our guide to box bar sizes and gauges for why sealing and painting steel is what decides how long it lasts.

Common questions

What size paint brush is best for walls?

Three to five inches for the open area, with a 2 inch brush for cutting in along the ceiling, corners and around switches. Most people use a roller for the main area and brushes for the edges.

Can I use the same brush for emulsion and enamel?

Only if it is cleaned thoroughly in between — water for emulsion, thinner for enamel. In practice it is easier and cheaper to keep separate brushes for each.

How do I stop a paint brush going hard?

Clean it the same day, in the right solvent, working the paint out of the root rather than just the tips. Then dry it hanging or flat, never standing on the bristles.

What brush do I need for painting a door?

A 2 inch and a 3 inch. Use the 2 inch for panels, mouldings and edges, and the 3 inch for the flat areas.

Need help choosing? Call +94 71 302 4843, message us on WhatsApp, or send your list through Request a Quote. WPL Trading, No. 305, Kandy Road, Dummaladeniya, Warakapola — open every day, 9.00 a.m. to 6.30 p.m., with island-wide delivery.