Brush: The Painter's Tool, From Paleolithic Reeds to Modern Synthetic Fibers

The oldest brushes ever found were made of animal hair. Humans have been using brushes to apply pigment for as long as they have been making images, which is to say for tens of thousands of years. The basic principle has not changed. A bundle of fibers is fixed to a handle, dipped in a liquid pigment, and dragged across a surface. What has changed is the precision of the tool. A Paleolithic brush made from a chewed stick is a blunt instrument. A modern Kolinsky sable round size 4 can paint a line thinner than a human hair. The gap between those two tools is the history of brushmaking.

An artist's brush is a tool consisting of a handle, a metal band called a ferrule, and a bundle of fibers called the tuft or bristles. The tuft holds and applies paint. The ferrule secures the tuft to the handle. The handle provides grip and control. Brushes come in different shapes, sizes, and fiber types, each designed for specific painting media and techniques. The shape of the tuft determines the kind of mark the brush makes, and the fiber type determines how the brush handles paint.

This entry covers the main brush shapes, the different hair and fiber types, the history of brushmaking from ancient times to the present, and how to choose brushes for different painting media.

What Is a Brush and How Does It Work?

A paintbrush works by capillary action. The fibers of the tuft hold liquid paint between them, and when the brush touches a surface, the paint transfers from the fibers to the surface. The amount of paint a brush holds depends on the fiber type, the length of the tuft, and how tightly the fibers are packed. Soft, absorbent fibers like sable and squirrel hold more liquid paint and release it smoothly, which makes them ideal for watercolor and ink. Stiff fibers like hog bristle hold thicker, heavier paint and push it across a surface with resistance, which makes them suited for oil and acrylic.

Three components make up every brush. The handle is typically made of wood, lacquered or varnished for protection, though some modern brushes use acrylic or aluminum handles. The ferrule is a metal band, usually nickel-plated brass or aluminum, that crimps the tuft and secures it to the handle. The tuft is the working part, made from natural hair, synthetic fiber, or a blend.

The invention of the metal ferrule was the most important development in brush history. Before the ferrule, brushes were made by inserting hair into the hollow quill of a feather, which limited the brush to a round shape. The ferrule, developed by professional brushmakers in the 18th century, allowed manufacturers to crimp the tuft into any shape. By squashing the ferrule flat, they could make flat brushes. This innovation, adopted by the Impressionists in the 19th century, transformed what painters could do with a brush.

Brush Shapes and What They Do

Round

Round brushes have a pointed or blunt tip with closely arranged bristles in a circular cross-section. They are the oldest brush shape, used for centuries before the ferrule made other shapes possible. Rounds can create modulated, linear marks by applying more or less pressure during the stroke. A pointed round is ideal for fine detail, lines, and lettering. Used on its side in a scribbling motion, a round makes an irregular, broken patch of color. Leonardo da Vinci, Rembrandt, and Vermeer all used round brushes made from animal hair tied to wooden handles, because that was the only type available.

Flat

Flat brushes have long bristles with a square edge, created by crimping the ferrule into a rectangular shape. They lay smooth patches of color, make long bold strokes, and can execute fine crisp lines when used on their edge. Marks made with a flat brush have a distinctive square end. Flats are versatile and are the workhorse brush for many oil and acrylic painters. A variation called a bright is a flat brush with shorter bristles, which generates more resistance against the surface and is good for short, strong strokes of color.

Filbert

Filberts are long-bristled flat brushes with a rounded tip. They combine the coverage of a flat with the softer edge of a round. Filberts are a favorite of figurative painters because they can create a variety of marks from broad to linear without the square edge of a flat. Used on its side in a scribbling motion, a filbert can make a flat patch of color with no distinctive brush marks. Used with dry pigment on the tip, it can achieve scratchy textures and blurred edges. The filbert is the most versatile brush shape for oil painting.

Fan

Fan brushes are splayed flat brushes with a round tip, shaped like a hand fan. They are not used to create the bulk of a painting. Fans are used for blending and softening hard edges, for stippling or flicking paint onto the canvas to create texture, and for depicting grasses, foliage, and fur. Fan brushes are typically made with soft hair to avoid picking up too much pigment.

Rigger (Liner)

Rigger brushes are round brushes with very long bristles, traditionally used for painting the rigging in pictures of ships. They hold a large amount of fluid paint and release it in long, flowing lines. Riggers are useful for fine details, calligraphic marks, and lettering in oil, acrylic, ink, or watercolor.

Hair Types and Fiber Materials

Hog Bristle

Hog hair, also called China bristle or Chunking bristle, comes from pigs and is one of the oldest and most commonly used brush materials. It is coarse, strong, and responsive, with natural split ends called "flagging" that help it carry thick, heavy-bodied paint. Hog bristle is the traditional choice for oil painting because it can push viscous paint across a surface without bending. The hairs are "dressed" so that the natural curl points inward toward the brush tip. Hog brushes are designed for vigorous techniques like impasto, scumbling, and dry brush. A worn hog brush becomes softer and can still be useful for gestural marks and blending, which is unusual among brush fibers.

Sable (Kolinsky Sable)

Sable is considered one of the finest hairs for artist brushes. What brushmakers call "sable" is actually hair from the Siberian weasel (Mustela sibirica), particularly the Kolinsky sable from the tail of the male animal. Kolinsky sable combines softness, spring, and absorbency, making it ideal for controlled strokes and delicate washes in watercolor. It holds a large amount of liquid paint and releases it smoothly. A high-quality Kolinsky sable round can hold a point sharp enough for hair-thin lines. These brushes are expensive because the supply of Kolinsky hair is limited and the manufacturing process is labor-intensive. Other red sables, ox hair (sold as "sabeline"), squirrel, goat, mongoose, and badger hair are also used for softer brushes.

Synthetic Fiber

Synthetic brush fibers were first developed in the 20th century. Nylon was invented in 1938 by Wallace Carothers at DuPont, followed by polyester in the 1940s and acrylic in the 1950s. Modern synthetic brushes are made from multi-diameter extruded nylon, polyester, or Taklon fibers that mimic the qualities of natural hair. They are durable, consistent, and often cheaper than natural hair. Many synthetic ranges mimic sable or hog with excellent results and can improve on natural fibers, for example by making a hog bristle substitute that is not negatively affected by water. Synthetic brushes are the standard for acrylic painting, since acrylic paint does not require the absorbency of natural hair and synthetic fibers resist the chemical action of acrylic mediums. Solvent-resistant synthetic bristles have been developed that are suitable for oil painting as well.

History of Brushmaking

Brushes have been used since the Paleolithic era. Ancient Egyptian brushes were made of split palm leaves, used to decorate tombs and temples. The Egyptians also used frayed papyrus for drawing and painting. In China, brushes for writing characters can be traced back at least 6,000 years, with long hair characteristic of calligraphy brushes that are still used today. The Greeks and Romans left written records describing how to make brushes.

In the 15th century, European brushes were made of animal hair inserted into the quills of bird feathers. The natural shape of quills limited brushes to round forms. This constraint shaped the painting of the Renaissance and Baroque periods. Every painting by Leonardo, Michelangelo, Raphael, Rembrandt, and Vermeer was made with round brushes, because flat brushes did not exist.

Until the end of the 17th century, painters and their apprentices made their own brushes. The profession of brushmaker was established in the 18th century, and it was these specialists who invented the metal ferrule. The ferrule freed the brush from the quill's round constraint. By crimping the ferrule, manufacturers could produce flat, filbert, bright, and fan shapes. The Artsy guide to paintbrush types notes that flat brushes were embraced by the Impressionists, who used them to create the broken, visible brushwork that defined the movement. Monet, Renoir, and Pissarro all adopted flat brushes in the 1860s and 1870s, and the square-ended brushstroke became a signature of Impressionist painting.

The 20th century brought synthetic fibers, which democratized quality brushes. A good synthetic round costs a fraction of what a Kolinsky sable round costs and performs well enough for most painters. The Jackson's Art guide to brushes documents the development of synthetic fibers and their increasing adoption across all painting media.

Brushes for Different Media

Oil painters typically use hog bristle brushes for heavy paint application and sable or synthetic soft-hair brushes for detail and blending. Oil brushes usually have long handles, sometimes 10 to 12 inches, so the painter can hold the brush at the end and stand back from the canvas. The long handle also allows the painter to rest the brush against the mahl stick for steady detail work.

Watercolor painters use soft hair brushes, traditionally Kolinsky sable, squirrel, or goat, though synthetic alternatives are now common. Watercolor brushes are made to hold large amounts of liquid and release it smoothly. They typically have short handles because watercolor painters work seated at a table or with the paper flat.

Acrylic painters use almost entirely synthetic brushes. The acrylic polymer in acrylic paint can damage natural hair over time, and synthetic fibers are more resistant to the chemical action of acrylic mediums. Stiff synthetics mimic hog bristle for heavy-body acrylic, while softer synthetics mimic sable for fluid acrylic and detail work.

How to Choose and Care for Brushes

Match the brush to your medium. Hog bristle for oil, sable or soft synthetic for watercolor, stiff synthetic for acrylic. Within each medium, choose brush shapes based on the marks you want to make. A basic set for oil painting might include two or three filberts in different sizes, a round for detail, and a flat for broad coverage. For watercolor, three or four rounds in different sizes plus a flat for washes will cover most needs.

Clean brushes immediately after use. Oil brushes should be wiped clean, rinsed in solvent, then washed with soap and water until the water runs clear. Acrylic brushes should be rinsed in water frequently during use, because acrylic paint dries quickly and permanently. Once acrylic paint dries in a brush, the brush is ruined. Watercolor brushes should be rinsed in clean water and reshaped with the fingers, then dried horizontally or hung brush-down to dry.

Store brushes flat or hanging brush-down. Never store brushes bristle-up in a jar, as water or solvent trapped in the ferrule will corrode the metal and loosen the tuft. For more on the tools that work alongside brushes, read our entries on the palette, the palette knife, and the easel. For a deeper understanding of how brushwork creates surface effects, see our entries on impasto and broken color, or read our post on oil painting techniques.