Brushes & Color
Watercolor Brush Selection and Color Mixing
The brush a watercolorist uses determines not just how paint reaches the paper, but how much control exists over water volume, edge quality, and stroke shape. Color mixing in watercolor follows different principles than oil or acrylic — transparency and pigment properties such as staining, granulation, and lightfastness affect how colors interact on paper and in the palette. This article covers brush types and their practical applications, then addresses color mixing principles relevant to transparent watercolor work.
Brush Types and Their Characteristics
Round Brushes
Round brushes are the most common form in watercolor work. A well-made round holds a large water and pigment reservoir in its belly while tapering to a fine point at the tip. This combination — water capacity plus point precision — makes it useful across a range of stroke widths depending on pressure. Size 8–12 rounds handle most general watercolor work; size 4–6 rounds work for detail passages; size 14–20 rounds suit large washes.
Kolinsky sable rounds hold the sharpest points and have strong spring (snap-back to tip position). Synthetic rounds have improved considerably and perform acceptably for most techniques at lower cost. In Poland, natural hair brushes from European manufacturers (Da Vinci, Escoda, Raphael) are available through specialist art suppliers in larger cities.
Flat Brushes
Flat brushes have a broad, straight edge that deposits paint in clean rectangular strokes. They suit architectural subjects, flat washes across defined areas, and dry brush work — the wide edge drags across paper texture, breaking the stroke cleanly. A flat in 20–25mm width functions as a wash brush for medium-scale work without carrying as much water as a large round or mop.
Mop Brushes
Mop brushes have a large, rounded head with high water capacity and no sharp point. Their purpose is delivering large amounts of wet pigment to paper quickly — useful for pre-wetting sheets, laying broad background washes, and wet-on-wet work where point precision is not needed. They are not suited to detail work. Squirrel hair mops hold the most water; synthetic mops are lighter but adequate for pre-wetting and broad wash applications.
Rigger / Liner Brushes
A rigger (also called a liner or script brush) has a very long, thin body of hairs and a fine tip. It holds enough paint for extended continuous lines — useful for ship rigging in marine paintings (the historical origin of the name), tree branches, wire, grass details, and any subject requiring long uninterrupted lines. Pressing a loaded rigger against paper and pulling slowly releases paint continuously without reloading.
Fan Brushes
Fan brushes spread hairs in a semicircular shape. In dry brush work, a fan brush dragged lightly across rough paper produces a texture suitable for grass, foliage, water surface, or stone. They are specialized tools — not necessary for general painting but useful for these specific texture applications.
| Brush Type | Best Use | Water Capacity |
|---|---|---|
| Round (8–14) | General work, mixed technique | High |
| Flat (20mm) | Washes, dry brush, edges | Medium |
| Mop | Pre-wetting, broad washes | Very high |
| Rigger | Fine continuous lines | Low |
| Fan | Dry brush texture | Low |
Color Mixing in Watercolor
Watercolor color mixing differs from opaque media in that pigment remains semi-transparent even after drying. Colors mix optically on the paper as well as physically on the palette. Understanding a few key pigment properties makes mixing results more predictable.
Transparency and Opacity
Most artists' grade watercolor pigments are transparent or semi-transparent. A few are naturally opaque — Cadmium Yellow, Cerulean Blue (not Phthalo), and Yellow Ochre among them. Mixing opaque pigments into transparent ones reduces the luminosity of transparent layers. For glazing — layering translucent washes over dried earlier washes — transparent pigments produce cleaner results than opaque ones.
Pigment transparency ratings are printed on most professional watercolor tubes and pans as a square symbol: open square = transparent, half-filled = semi-transparent, filled = opaque. Schmincke and Winsor & Newton both include this information on tube labels.
Granulation
Some pigments — French Ultramarine, Burnt Sienna, Raw Umber, Manganese Blue Hue — granulate naturally when applied in a wet wash on cold press or rough paper. They separate into visible particles that settle into the paper's valleys, creating a textured, uneven appearance even in a single flat wash. This property is desirable in certain contexts (stone, sky, weathered surfaces) and unwanted in others (smooth skin, flat architectural areas). Testing an unfamiliar pigment on a scrap of the same paper before committing to a full painting reveals its granulation tendency.
Staining Pigments
Staining pigments penetrate paper fibres and cannot be fully lifted after drying. Phthalo Blue, Phthalo Green, and Quinacridone Magenta are common staining pigments. When used in the initial layers of a painting, they permanently alter the paper surface in those areas — corrections involving lifting become impossible. Non-staining pigments (French Ultramarine, Raw Sienna, Cerulean Blue) lift more cleanly from the paper surface and allow more correction.
Mixing for Neutrals and Darks
In transparent watercolor, mixing three pigments to produce a neutral dark risks creating mud — a flat, lifeless grey-brown with no optical depth. More controlled approaches:
- Mix two complementary colors (opposite on the color wheel) for neutrals: Ultramarine + Burnt Sienna, or Phthalo Green + Quinacridone Red. The resulting neutral retains some chromatic character from each parent pigment.
- Use single-pigment darks where possible: Indigo, Payne's Grey, or Neutral Tint are single or two-pigment darks that mix cleanly with other colors.
- Layer transparent glazes to deepen value rather than mixing high-pigment concentrations on the palette — multiple thin washes of the same transparent color build depth without muddying.
Wet Palette vs Dry Pan Color
Tube watercolors in a wet palette stay moist and mix immediately when touched with a damp brush. Pan sets require rehydrating the pigment with water before use — adding a drop of water to each pan a few minutes before beginning a session prevents scrubbing the pan surface with a dry brush, which damages pan texture over time. Both formats produce equivalent results; the choice depends on whether portability (pans) or immediate pigment availability (tubes) is more important for a given working context.
External References
Pigment database and transparency ratings: winsorandnewton.com. Brush specifications: jacksonsart.com. Schmincke pigment information: schmincke.de.