A medium round is a flexible first choice for detail, lines and washes, and can also make broad strokes and a point. Add a flat or bright to cover a larger area or a mop or wash brush for broad washes, then choose synthetic, natural hair or a blend by the handling qualities you want. Brush numbers vary between makers and ranges, so compare the actual head and product description rather than buying by size number alone.
Choose a watercolor brush for the marks you want to make, then compare head size and hair type. A small, practical group usually gives a beginner more control than a large set of shapes they may not use.
Choose the brush shape for the mark
| Shape | Useful for | Compare |
|---|---|---|
| Round | Fine detail, lines and washes; a round brush can also make broad strokes and form a point. | Point quality, belly size and head dimensions. |
| Flat or bright | Blending, glazing or covering a large area. | Head width and whether the shape suits the marks you want. |
| Mop or wash | Broad washes with thinned color and larger areas. | Brush size and its capacity for water and pigment. |
The brush belly is its widest part; Winsor & Newton says a fuller belly can carry more water and paint. It also lists shapes such as filbert, fan and rigger, so compare the maker’s description of the exact mark before adding a specialty brush.
Compare natural, synthetic and blended hair
Brush hair changes how the head feels and carries color. Winsor & Newton describes natural hair brushes as soft and flexible, with different natural fibers suited to different handling. In its examples, sable holds a fine point for controlled marks, while squirrel carries more water and is used for mop and wash brushes.
Synthetic brushes are an option when you prefer not to use natural hair or want a lower-cost line. Soft synthetic bristles can suit watercolor, and some synthetic sable blends are designed to combine qualities of natural and synthetic brushes. Compare the maker’s description for the exact brush instead of assuming that every brush in a material category behaves alike.
Match the size to your painting
Brush numbers are not a universal measurement. Winsor & Newton notes that sizes can differ between ranges, including English, French and Japanese numbering. Compare the brush head’s actual width, length and belly, and check whether the listed size belongs to a round, mop or another shape.
Use a smaller head when the work is mostly fine detail. If you paint broad washes, a larger belly may reduce repeated reloading. A short handle can suit a painter who works close to the paper; choose a longer handle if that is more comfortable for your setup.
A useful first set
Start with a medium round and add one tool for the work you do most: a flat for broad, crisp marks or a mop/wash brush for larger wet areas. If you are comparing sets, check that the shapes, sizes and hair types are named clearly and that the set does not duplicate brushes you already own.
Our watercolor paper guide explains how paper texture and weight affect a painting surface. If you are still choosing a medium, compare acrylic, oil and watercolor. Browse art supplies for more materials and tool advice.
Official sources
Checked November 5, 2026.
- Winsor & Newton: What brush shape and size is best for watercolour?
- Winsor & Newton: What type of brush hair is best for watercolour?
- Winsor & Newton: Watercolour brushes
- Winsor & Newton: Your top ten watercolour questions answered
- Winsor & Newton: Cotman Series 111 round watercolor brush
- Winsor & Newton: Cotman Series 555 short flat/bright watercolor brush
- Winsor & Newton: Synthetic sable mop watercolor brush
Common questions
What watercolor brush should a beginner buy first?
A medium round is a practical first choice for detail, lines and washes. Add a flat or a mop when you regularly need to cover a broad area.
Are natural hair brushes better than synthetic brushes for watercolor?
Neither is the right choice for everyone. Natural hair types have different handling qualities, while synthetic brushes can offer a useful alternative at a lower price; compare the exact maker's description, brush shape and how much water the head carries.
Do watercolor brush size numbers match across brands?
No. Winsor & Newton notes that the same number can refer to different brush sizes across ranges, so compare the head's actual dimensions and shape before ordering.