Watercolor: Transparent Water-Based Paint on Paper

Hold a watercolor painting up to the light and the paper shines through the paint. This is the defining quality of the medium. The white of the paper is not a surface to be covered but a light source that glows through transparent washes of color. No other painting medium works this way. In oil painting, the white ground is covered and built upon. In watercolor, the paper is the painting. Every area of white in a watercolor is paper that was never touched by the brush, and once a mark is made, it cannot be fully erased or painted over without losing the luminosity that makes the medium distinctive.

Watercolor is paint made of pigment suspended in a water-soluble binder, traditionally gum arabic, applied with water onto absorbent paper. The binder holds the pigment to the paper surface but does not form a thick, opaque film. The paint sinks into the paper fibers and dries by evaporation, leaving a thin, transparent layer of color. Because the binder is water-soluble, the paint can be reactivated with water even after it dries, which allows for blending and lifting but also means the finished work is fragile and sensitive to moisture.

This entry covers how watercolor works, its history from manuscript illumination to contemporary practice, the artists who defined it, and what to look for when you stand in front of a watercolor painting.

What Is Watercolor and How Does It Work?

The components of watercolor paint are pigment, gum arabic (the binder), water (the solvent), and sometimes additives like glycerin (to retain moisture), honey (for flexibility), or ox gall (to improve flow). Gum arabic, the dried sap of the acacia tree, is the traditional binder. It dissolves in water, forms a thin, transparent film when dry, and can be redissolved with water. This reactivity is both a feature and a vulnerability. Painters can lift and rework dried washes, but finished paintings can be damaged by humidity, spills, or even the moisture in a person's breath.

The paper is as much a part of the medium as the paint. Watercolor paper is made from cotton or wood pulp, sized with gelatin or synthetic sizing to control absorbency. The paper's texture, called its "tooth," ranges from smooth (hot pressed) to heavily textured (rough). The texture affects how the paint settles into the fibers and creates the granulation patterns that watercolorists exploit for visual effect. Heavy pigments like ultramarine and cerulean blue settle into the paper's valleys, creating a mottled, granular texture, while fine pigments like phthalocyanine spread evenly across the surface.

The transparency of watercolor comes from the ratio of pigment to binder and the absence of white filler. Watercolor paint contains no white pigment. The lightness in a watercolor comes from the paper showing through the transparent color layer. This is why watercolorists work from light to dark, building up darker values with successive washes while preserving the white of the paper for the lightest areas. A 2025 study published in Heritage used reflectance imaging spectroscopy and portable XRF to identify pigments in 1930s watercolors from the Arxiu Valencia del Disseny, finding Prussian blue, chrome yellow, and alizarin red among the colors used. The research demonstrated how modern non-invasive techniques can document watercolor palettes without sampling. Read the study at MDPI Heritage.

History and Origins

Watercolor's roots go back to the earliest water-based paints used in ancient Egypt, China, and the Islamic world. In medieval Europe, water-based paints bound with gum arabic, egg white, or animal glue were used for illuminated manuscripts. Albrecht Durer (1471-1528) is widely credited as the first European artist to use watercolor as an independent fine art medium rather than a decorative or preparatory tool. His nature studies, including the famous Young Hare (1502, Albertina, Vienna), demonstrate a level of observation and technical control that established watercolor as a medium for serious artistic work.

The medium developed most fully in Britain between 1750 and 1850, a period sometimes called the "Golden Age of Watercolor." Thomas Girtin (1775-1802) pioneered broad, atmospheric washes that captured landscape and weather rather than topographical detail. His contemporary J.M.W. Turner (1775-1851) pushed the medium further than anyone before him, using watercolor to create dramatic, luminous studies of light, atmosphere, and weather that rivaled his oil paintings in ambition. A 2025 blog post from the INFR-ART research group at the National Institute of Research and Development for Optoelectronics traces this history in detail, noting how Turner's experience with oil painting informed his increasingly dramatic watercolor approach. Read the article at INFR-ART Blog.

In the 19th century, watercolor spread globally. American painters like Winslow Homer (1836-1910) and John Singer Sargent (1856-1925) used it for direct, expressive work that took advantage of the medium's portability. A comprehensive scientific study of 59 Homer watercolors from the collections of the Art Institute of Chicago and the National Gallery of Art, Washington, published by the Royal Society of Chemistry, examined his palette and techniques in detail, revealing his increasing technical complexity and deliberate exploitation of individual pigment properties. Read the research at RSC Publishing.

Key Artists and Masterworks

Albrecht Durer (1471-1528)

Durer's Young Hare (1502, Albertina, Vienna) and his landscape watercolors like View of Arco (1495, also Albertina) show the medium's potential for precise observation. Durer used watercolor to record the natural world with a fidelity that would influence naturalistic illustration for centuries. His technique involved careful, layered washes that built up form and texture without losing the luminosity of the paper.

J.M.W. Turner (1775-1851)

Turner produced hundreds of watercolors, from topographical studies to near-abstract evocations of light and atmosphere. His The Blue Rigi, Lake Lucerne (1842, Tate, London) is a masterwork of the medium, using minimal washes to create a mountain that seems to materialize from mist. Turner's watercolors were so atmospheric that some contemporaries accused him of painting "tinted steam."

Winslow Homer (1836-1910)

Homer painted approximately 685 watercolors between 1873 and 1905. Works like The Blue Boat (1892, Museum of Fine Arts, Boston) and his Bahamas series show a directness and confidence that exploits watercolor's ability to capture fleeting effects. Homer often left large areas of paper untouched, letting the white of the sheet represent blinding tropical light.

John Singer Sargent (1856-1925)

Sargent used watercolor for rapid, fluid studies during his travels. His White Ships (c. 1908, Museum of Fine Arts, Boston) and Venetian scenes use bold, economical washes that capture light and water with a precision that his more deliberate oil portraits rarely match. Sargent's watercolors are among the most technically accomplished in the medium's history.

Paul Cezanne (1839-1906)

Cezanne's watercolors are structurally different from Homer's or Sargent's. He used thin, overlapping washes to build form through color relationships rather than description. Three Pears (c. 1888-1890, private collection) shows how he used the white of the paper as an active compositional element, with patches of untouched paper creating light and space within the composition.

How to Look at a Watercolor

When you look at a watercolor, the first thing to notice is the paper. Every white area is paper that the painter left unpainted. In Homer's tropical watercolors, the blinding white of the sun and the glare on water are simply bare paper. In Turner's landscapes, the luminous quality of distant mountains comes from a single, thin wash over white paper, not from white paint.

Look for the edges of washes. A hard edge means the paper was dry when the wash was applied. A soft, feathered edge means the paper was wet, allowing the paint to spread into the fibers. Watercolorists call these "wet-on-dry" and "wet-on-wet" techniques, and the contrast between them creates much of the visual interest in a watercolor.

Look for granulation, the mottled texture that appears when heavy pigment particles settle unevenly into the paper's texture. Ultramarine and cerulean blue granulate heavily, while phthalocyanine and quinacridone colors spread smoothly. Painters choose pigments partly for their granulation behavior, using it to create texture in skies, water, and natural surfaces.

Watercolor Today

Watercolor is experiencing a renaissance in the 21st century. A 2025 study in the World Journal of Advanced Research and Reviews examined contemporary trends, finding that modern watercolor practice increasingly combines traditional techniques with mixed media approaches, including acrylic gels, modeling pastes, and digital tools. The study identifies two key trends: the use of unconventional texturing materials and the digital transformation of watercolor, including 3D modeling software that simulates watercolor effects. Read the study at WJARR.

Contemporary watercolorists like Joseph Zbukvic and Thomas Schaller continue to explore the medium's capacity for capturing light and atmosphere. The medium's directness, the fact that every stroke is visible and cannot be hidden under subsequent layers, remains its essential challenge and its essential appeal.

See Watercolor in Person

Watercolors are light-sensitive and cannot be permanently displayed, which makes seeing them in person both special and rare. Museums rotate watercolor exhibitions to limit light exposure. The Albertina in Vienna holds the largest collection of Durer watercolors. The Tate in London has an extensive Turner collection. The Museum of Fine Arts in Boston holds significant Homer and Sargent watercolors.

When you do see them, notice how the paper glows through the paint. That luminosity is what distinguishes watercolor from every other painting medium. For more on related water-based paints, read our entries on gouache and tempera, or explore our blog post on how to read a painting to learn more techniques you can spot in museums.