A Brush Size Guide That Actually Makes Sense

Brush size numbers (like a "size 8" round) aren't a universal measurement — they're brand-specific, and a size 8 from one manufacturer can be visibly different from a size 8 from another. What's consistent is the relative scale within a single brand's range: a size 12 is always bigger than a size 8 from that same maker.

For watercolor, a good minimal kit is one round in the 6–8 range for general work, a smaller round (size 2–4) for detail, and a larger round or flat (size 12+) for big washes and skies.

Brush shape matters as much as size: rounds taper to a point and are the most versatile; flats give crisp edges and are useful for architectural or geometric work; filberts split the difference with a rounded flat edge good for soft blending.

When in doubt, buy one size up rather than down — a slightly bigger brush forces looser, more confident strokes, which is usually the better habit to build.