Paper, Water, and Brush — The Other Half of the Palette
What you paint on and with matters as much as what you paint in
A guide to the surfaces, tools, and fluid decisions that determine whether your pigments sing or suffer
The Invisible Variable
Here is a test. Take a single pigment — French Ultramarine, say, or Burnt Sienna — and paint identical washes on five different papers: Arches cold press, Fabriano Artistico hot press, Saunders Waterford rough, a sheet of Japanese kozo, and whatever student-grade wood pulp pad is nearest to hand. Let them dry completely. Then compare.
What you will see is not five versions of the same result. You will see five genuinely different paintings — different granulation, different edge behavior, different drying time, different luminosity, different color depth, different surface texture reading against the pigment. The Arches wash will granulate distinctly and hold its edges cleanly. The Fabriano hot press will produce a smooth, glassy result with almost no granulation. The Saunders rough will create a broken, speckled passage where the pigment skips across the peaks of the paper's texture. The kozo will absorb the pigment immediately and spread it organically in all directions. The student-grade pad will buckle, absorb unevenly, and probably pill if you try to lift.
Same pigment. Same brush. Same water. Five different paintings.
This is the fundamental truth about watercolor that no amount of pigment knowledge addresses: the surface is not a passive recipient. It is an active participant. And the brush and the water are not merely delivery mechanisms — they are the means by which you manage the relationship between pigment and surface in real time, under conditions that change by the minute as the water evaporates and the paint sets.
The palette is one half of the practice. This is the other half.
Part One: Paper
The Long History of a Quiet Material
Paper is older than most people assume and more consequential than its humility suggests. The oldest surviving piece of paper in the world was discovered in 1957 near Sian in Shensi province, China, and dates to somewhere between 140 and 87 BCE. The Chinese court official Ts'ai Lun is credited in records from 105 CE with refining the process — bark of trees, hemp, rags, and water, mashed to pulp, pressed, and dried in the sun — and it is from this tradition that the entire subsequent history of paper derives.
Paper reached Europe via the Arab world in the 11th and 12th centuries, and it arrived in Italy first. Fabriano, Italy, began papermaking in 1283, when paper production flourished with the use of recycled linen rags for pulp. The town of Fabriano — a small city in the Marche region of central Italy — became the center of European papermaking for centuries, and its name is still on the tubes of paper that professional watercolorists use today. There is a Paper and Watermark Museum in Fabriano that documents this history and is worth a detour for the seriously curious traveler.
The Arches paper mill was founded in Lorraine, France, in 1492. Its founding year — the same year Columbus reached the Americas, the same year the Moors were expelled from Spain — places it at the precise hinge of the medieval and modern worlds. The Arches mill gained early recognition by providing paper for the Nuremberg Chronicle, one of the most renowned illustrated books of the early printing era. Later, in the 18th century, Pierre Beaumarchais used Arches paper to publish the complete works of Voltaire — requiring 70 tonnes of paper — further enhancing the brand's reputation. Napoleon's monumental Description of Egypt, printed between 1807 and 1823, required two million sheets of Arches paper, made by hand. The paper that carries Turner's washes and Sargent's mercurial marks has been made in the same village, by variants of the same process, for more than five centuries.
In 1826, while other mills switched to cheaper, less durable sizing methods, Arches made the strategic decision to retain its traditional gelatin sizing. This choice preserved the paper's archival quality, cementing Arches as the preferred paper for fine art, printing, and bookbinding. That decision, made two hundred years ago, is the direct reason why Arches paper behaves the way it does today — why washes sit on the surface longer, why lifting is more reliable, why the paper can be reworked aggressively without pilling.
What Paper Actually Is: Cotton, Sizing, and Surface
Understanding watercolor paper requires understanding three things: fiber content, sizing, and surface texture. Everything else — weight, format, brand, color — is secondary to these three.
Fiber Content
Cotton fibers are strong, flexible, naturally white, and acid-free, making them ideal for archival watercolor paper. Wood pulp papers are cheaper but tend to yellow, become brittle, and degrade faster. Most professional watercolor papers are 100% cotton, offering superior durability and paint handling that make them worth the extra cost.
This is not a matter of preference or budget optimization. It is a structural requirement. Wood pulp paper contains lignin — the organic compound that gives trees their rigidity — which oxidizes over time, yellowing and embrittling the paper. The acid this produces destroys the paper fibers and, more slowly, the pigment layers above them. Cotton rag paper contains no lignin. It is pH-neutral, acid-free, archival, and will outlast every wood pulp surface indefinitely.
The practical implication is stark: student-grade paper is not a stepping stone to professional paper. It is a fundamentally different material. You can learn certain things on it — value relationships, compositional decisions, color mixing — but you cannot learn how professional paper actually behaves, because it doesn't behave the same way at all. Serious practice requires serious paper. The cost differential per painting is smaller than it appears.
Sizing
Sizing is the agent — typically gelatin (animal-derived) or synthetic substitutes — that is applied to watercolor paper to control how quickly water and pigment are absorbed. Without sizing, a watercolor wash would sink immediately into the paper fibers, spreading uncontrollably and losing luminosity. Sizing creates a controlled barrier that allows the painter to work wet passages before they set.
Sizing comes in two forms: internal (incorporated into the paper fibers during manufacture) and external (applied to the surface of the finished sheet). The combination of both, as in Arches, produces the hardest-sized paper in the professional range.
Arches is the only mould-made paper that is sized on the machine and then additionally has an extra hit of sizing in an off-the-machine size bath. It is considered a hard-sized sheet to those who use it and consequently will take an enormous amount of surface abuse. One can repeatedly rub out, wash out, and rework an area without fear of the paper's surface fiber lifting off or pilling.
Fabriano Artistico uses internal and external sizing that is not animal-derived, making it suitable for vegan painters. Saunders Waterford uses a combination of internal and surface sizing that is entirely gelatin-based. These distinctions matter not only ethically but practically: gelatin sizing tends to produce a slightly harder, more resistant surface than synthetic sizing, which is one reason Arches and Saunders behave differently from manufacturers using synthetic alternatives.
A crucial practical note: sizing degrades over time, particularly with exposure to humidity. Paper that has been stored for years in damp conditions may have lost significant sizing, causing washes to behave more like student-grade material even on expensive cotton rag stock. Store paper flat in dry conditions. If you suspect old paper has lost its sizing, a dilute gelatin solution can be applied and allowed to dry before painting — a technique documented in 19th-century technical manuals and still valid today.
Surface Texture
Hot press paper's smoothness means paint sits on the surface longer, allowing more control but less natural texture. Cold press paper's bumps cause pigment to pool in tiny valleys, creating natural granulation and subtle texture in washes. Rough press amplifies this effect with even bolder texture, perfect for expressive, atmospheric work.
The three surfaces are not a spectrum from beginner to advanced. They are different tools for different purposes.
Hot Press (smooth, pressed by heated rollers): the surface favored for botanical illustration, detailed architectural rendering, and any work where precision of line matters. Paint sits on the surface rather than sinking into texture, which allows for the finest possible brushwork and the cleanest possible edges. The same smoothness that enables precision also makes wet-into-wet work more challenging — without texture to hold and guide the wash, large wet passages can behave unpredictably, spreading in all directions. Sargent used hot press for some of his most precise Venice interiors. Dürer's nature studies, had they been painted rather than drawn, would have required hot press — his microscopic precision demands a surface that doesn't interrupt the stroke.
Cold Press (also called NOT — meaning Not Hot Press — in the British system): the universal working surface, textured enough to create natural granulation and atmospheric depth, smooth enough to allow controlled detail work. Cold press is the easiest to work with — it's forgiving, versatile, and well suited for learning. It is the surface on which most of the English Golden Age watercolors were painted, the surface Turner used for the bulk of his finished works, and the one Homer relied on for his American watercolor practice. If you paint on only one surface, this is the one.
Rough: the painter's rough — unpressed, with prominent peaks and deep valleys that dominate the character of any mark made on it. Rough press pulls lots of pigment from the brush making for intense colors. Granulating pigments on rough paper produce extraordinary effects — the physical separation of pigment particles into the valleys of the paper's texture, creating passages of almost crystalline atmospheric complexity impossible to achieve on smoother surfaces. The rough surface is also unforgiving: the prominent texture asserts itself against fine detail work and makes certain kinds of controlled precision essentially impossible. It is the surface for expressive work, for landscape, for sky passages, for the kind of painting that wants the paper to contribute its own voice.
The Major Papers: A Working Guide
Arches Aquarelle (France, founded 1492) The world standard. Arches is the most widely used professional watercolor paper, and for good reason. It has a robust surface sizing — gelatin-sized internally and externally, and dried in air, which gives it a distinctive surface feel. Colors stay vibrant and crisp. It can handle multiple heavy washes and aggressive lifting without pilling. The cold press texture is well-defined and consistent, making it ideal for a wide range of techniques from loose landscapes to tight rendering.
Its one notable challenge: because of its strong sizing, it's less forgiving to beginners — washes can bead up if you're not generous with water, and soft blends require a bit more finesse. The hardness that enables reworking also requires confidence in initial wash application. Timid, waterless strokes on Arches produce unpleasant streaks. Generous, wet, committed marks produce luminous results.
Available in 90 lb (185 gsm), 140 lb (300 gsm), and 300 lb (640 gsm). The 140 lb cold press in full sheets (22 × 30 inches) is the working standard for most professional watercolorists.
Fabriano Artistico (Italy, founded 1283) Fabriano Artistico is prized for its even surface and beautiful color response. Where Arches has a distinctive tooth and hard sizing, Fabriano is softer and more immediately receptive — washes spread more quickly and blend more easily, which makes wet-into-wet work more intuitive but fine detail work slightly less controlled. Its surface is slightly warmer in tone than Arches's bright white.
Fabriano's 740 years of continuous papermaking is the longest of any surviving mill. That history has a museum in the original town, and the watermark — the crown and "F" — that appears in transmitted light on every sheet is itself a document of continuity stretching back to the Renaissance workshops. There is something quietly satisfying about painting on material made in the same place by variants of the same process for seven centuries.
Saunders Waterford (England — St. Cuthberts Mill, Somerset) Often called "the British Arches," Saunders Waterford offers beautiful texture and slightly gentler sizing than Arches. It's less hard-surfaced than Arches but more structured than Fabriano. This gives a great balance for expressive watercolorists who still want structure. It handles multiple washes well, and the rough surface is particularly stunning — it catches pigment in ways that make granulating paints sing. Best for: loose painters, granulation lovers, landscape work, expressive glazing.
St. Cuthberts Mill in Somerset has been producing paper since the 18th century, and Saunders Waterford remains the preferred paper of many British plein-air painters. Its gelatin sizing is slightly softer than Arches, giving a working feel that many describe as more immediately sympathetic — the paper feels like it is cooperating rather than resisting.
Hahnemühle (Germany, founded 1584) The German mill that has been producing fine art papers since the year Shakespeare was born. Hahnemühle's watercolor range offers surfaces of exceptional consistency, particularly in their heavier weights. Hahnemühle's cold press surface is closer to Arches but a touch softer — excellent sizing, vibrant pigment response. Their hot press surfaces are among the finest available for botanical and detail work.
Japanese Washi and Kozo Papers An entirely different category. Washi — traditional Japanese paper made from plant fibers including kozo (paper mulberry), mitsumata, and gampi — behaves in ways that Western watercolor paper does not. It absorbs water immediately and completely, spreads pigment organically in all directions, produces no granulation, and dries with a translucent, almost glowing quality. It is the surface for ink wash painting, for sumi-e, for the kind of mark-making where the paper's absorption is used rather than resisted. For Western watercolor technique it is challenging because control is essentially impossible — which is also precisely why some painters love it. The ink and wash traditions of Japan and China were built on this kind of paper, and the marks those traditions produce are inseparable from its particular behavior.
Weight, Format, and Stretching
Standard watercolor paper is 300 gsm (140 lb). Heavier paper (640 gsm / 300 lb) needs no stretching. Lighter paper (190 gsm / 90 lb) will buckle with heavy water use.
Buckling occurs when one side of the paper absorbs water and expands while the other remains dry — the differential expansion creates waves and hills across the surface, causing wash to pool in valleys rather than spreading evenly. At 300 gsm, most papers will buckle under heavy wet-into-wet applications unless secured. At 640 gsm, they will not buckle at all.
Stretching — wetting the paper fully, allowing it to expand, then securing the edges with gummed tape on a rigid board and allowing it to dry taut — prevents buckling by pre-expanding the paper before painting begins. It is time-consuming and requires forward planning, but produces a perfectly flat working surface for even the wettest technique.
Blocks — sheets glued on all four sides, peeled off after completion — eliminate the need for stretching and are the working format most commonly used for location painting. The glued edges hold the paper flat through wet passages; once complete and dry, a palette knife or letter opener separates the sheet from the block. Using a watercolor block eliminates the need for stretching entirely, which is why blocks are so popular.
Part Two: Water
Water is discussed last in most guides. It deserves more attention than that.
The water in your rinse jars and mixing wells is not a neutral ingredient. Tap water in most cities and towns is treated with chlorine and often contains dissolved minerals that affect both the behavior of gum arabic binders and the chemical stability of sensitive pigments. Hard water — high in dissolved calcium and magnesium — can cause certain pigments to flocculate (clump) in the wash, producing uneven granulation that is not from the pigment's own properties but from mineral interference. Soft tap water behaves better, but the chlorine still affects gum arabic over time.
The professional solution is simple: distilled or filtered water. Not an expensive or complicated measure — a standard water filter removes chlorine and reduces mineral content sufficiently. The difference in wash behavior on sensitive pigments (particularly the quinacridones and phthalos) is noticeable, and the difference in the longevity of palette wells — which accumulate mineral deposits over time with hard tap water — is significant.
Two containers, not one. The single most common source of muddy painting is a dirty rinse jar. Use two: one for the initial heavy rinse after each color change, one for the final clean rinse before loading the next pigment. Change both regularly. The water in your clean rinse jar should be changed before it becomes noticeably colored. Most experienced painters change their rinse water every thirty minutes of active painting, more frequently in heavy work.
Water temperature is rarely discussed but matters for certain techniques. Room-temperature water produces more even wash behavior than cold water, which causes some pigments to thicken slightly on cold paper. Very warm water (not hot) can accelerate drying, which is occasionally useful for controlling wet-into-wet timing but rarely desirable otherwise.
Water quantity in the wash is the variable that most beginning painters underestimate. Watercolor washes require significantly more water than intuition suggests — a proper loaded wash should be visibly shiny and fluid on the paper, moving freely when the board is tilted. Stiff, underwatered washes drag on the paper surface, lift previous layers unpredictably, and dry with hard, chalky edges. The fear of "too much water" is the enemy of luminous watercolor; the actual enemy is too little.
Part Three: Brush
The Material Question
A watercolor brush must do three things simultaneously: hold a sufficient reservoir of pigment and water, release that reservoir in a controlled and even flow, and return to a precise point or edge immediately after each stroke. These requirements pull against each other, and the history of brush-making is the history of finding materials that satisfy all three as well as possible.
The answer that the craft settled on, over centuries, is Kolinsky sable.
Kolinsky sable watercolor brushes are made from the tail hair of the Siberian weasel (Mustela sibirica). They hold more water, snap back to a perfect point, and outlast every other natural hair brush. The specific quality that makes Kolinsky hair exceptional is structural: each hair tapers naturally from a thick base to an extremely fine tip, and has a microscopic surface texture that holds water through capillary action more effectively than any other natural or synthetic fiber. No synthetic fiber has ever perfectly replicated this shape. Only winter-harvested male tail hair meets the quality standard.
The combination of water-holding capacity and spring — the immediate return to point after each stroke — is what distinguishes Kolinsky from every alternative. Natural squirrel (especially Kazan squirrel) holds water as well as Kolinsky. Some artists argue squirrel holds even more. But squirrel hair has almost no snap. It's floppy. Kolinsky gives you both: the water capacity and the spring. That's why it commands a premium.
A quality Kolinsky round in size 10 — the most useful all-purpose watercolor brush size — costs between thirty and a hundred and fifty pounds or dollars, depending on brand and source. This is not an extravagance. A good Kolinsky brush, properly cared for, lasts years. The cost per painting hour is negligible. The cost of poor brushes — stiff, water-resistant, unable to hold a point, unable to deliver a consistent wash — is measured in frustration and ruined paper.
The major makers of Kolinsky brushes worth knowing:
Winsor & Newton Series 7: the canonical reference — the brush that defined the standard for a century. Handmade in England, every brush individually tested for point and spring before shipping. The Series 7 round is what most professional British watercolorists have used as their primary brush for generations.
Rosemary & Co (England): a small Yorkshire company founded by Rosemary and Bill Rosenvinge that produces handmade brushes of exceptional quality at prices meaningfully below the major brands. Their Kolinsky and squirrel ranges have developed a devoted following among professional watercolorists who discovered them largely through word of mouth.
Da Vinci (Germany): the Bavarian brush maker with the longest continuous production history, making brushes since 1890. Their Maestro Kolinsky series is particularly well-regarded. Their Casaneo series uses synthetic Kazan squirrel hair and is among the best synthetic options for large wash work.
Escoda (Spain): Barcelona-based, making brushes since 1933. Their Reserva Kolinsky line is excellent; their synthetic Versatil and Perla ranges are among the most sophisticated synthetics available — Escoda Versatil brushes are designed to mimic Kolinsky sable and succeed better than most.
The Ethics and Alternatives
The supply of genuine Kolinsky hair has become increasingly complicated. Sable hair has rocketed in price recently. Suppliers are becoming fewer and farther between. Also, if you live in the US, you may have noticed certain brushes are difficult to come by because of bans on importing sable hair. CITES (the Convention on International Trade in Endangered Species) regulations on the Siberian weasel have added compliance costs and supply constraints that are only likely to intensify.
The good news is that synthetic brush technology has advanced substantially. In blind tests, many intermediate artists can't distinguish a quality synthetic squirrel from Kolinsky for typical watercolor techniques. For wash work, wet-into-wet, and large-scale painting, synthetics perform admirably. The gap remains most noticeable in fine point work and detail passages, where the spring and tip precision of genuine Kolinsky is still difficult to fully replicate.
The pragmatic approach most professional painters have settled on: a few genuine Kolinsky rounds in the sizes used for detail and controlled work (sizes 6, 8, 10), supplemented by high-quality synthetic or squirrel brushes for large wash areas and mop work.
The Working Brush Collection
A working watercolor painter does not need many brushes. The painters who accumulate dozens are usually avoiding a different problem — the brush collection as postponement of painting. Here is what actually constitutes a complete working set:
The Round — sizes 6, 8, and 10 in Kolinsky or quality synthetic. The round is the primary instrument of watercolor. It holds a reservoir in its belly, releases controlled flow from its point, and can produce marks ranging from the finest detail (using the tip) to broad, sweeping strokes (using the full body of the brush loaded and pressed flat). Most professional watercolorists paint ninety percent of any work with rounds in this size range. If you have a size 10 round of quality and nothing else, you can paint anything.
The Mop — a large, full squirrel or synthetic squirrel brush for wetting the paper and laying initial background washes. The squirrel mop holds an extraordinary volume of water and delivers it evenly across large areas without streaking. For the initial wet paper preparation in wet-into-wet work, nothing else does the job as well. Da Vinci's Casaneo series is excellent here.
The Flat — a square-edged brush in 1/2 inch or 3/4 inch for architectural edges, clean geometric washes, and the specific kind of dry-brush mark that a flat produces when dragged across rough paper with a nearly-dry load. Sargent used a large flat extensively for his broad architectural passages.
The Rigger (also called a script liner) — a long, thin brush with a very fine point, used for rigging in marine painting (hence the name) and for any fine linear detail: branches, grasses, ship masts, wires, signatures. A single size 2 or 4 rigger handles all of this work.
Optional: the Hake — a Japanese broad flat brush made from goat or sheep hair, used for large-area wetting and initial sky washes. Soft, high-capacity, and inexpensive. Some painters swear by it for paper preparation; others never use one. Worth trying.
Brush Care
A Kolinsky brush that costs a hundred dollars and is properly cared for will outlast five brushes of equivalent quality that are not. The rules are simple and essentially never followed by anyone who hasn't ruined a brush first.
Never leave brushes resting on their tips in a water jar. The pressure bends the hairs permanently and no amount of reshaping recovers the point. Rest brushes flat, or point upward in a jar where the hairs are not in contact with the bottom.
Never use painting brushes for masking fluid. The latex destroys natural hair irreversibly and damages synthetic fibers significantly. Keep a dedicated cheap synthetic for masking fluid, and accept that it will need replacing periodically.
Clean brushes gently with mild soap and cool water after each session. Do not use hot water — it loosens the ferrule glue that holds the hairs in place. Reshape to a point with damp fingers and allow to dry horizontally.
Store brushes either horizontally or upright in a case or jar with hairs pointing upward. If storing for extended periods, a few cedar chips or moth deterrents protect natural hair from insects.
The Triangle
Paper, water, and brush form a triangle with pigment at the center. Change any one element and you change the painting. The painter who has worked through both the pigment articles and this one now holds the full picture: what goes into the paint, what it goes on, what it is applied with, and what the water that carries it needs to do.
This is more information than Turner had. He learned his paper empirically, working through reams of different surfaces across decades until he understood what each one would do with his washes. He learned his brushes by breaking them and replacing them and noticing what changed. He learned his water by watching what it did and adjusting.
That empirical education is still necessary. No article replaces the afternoon spent painting the same subject on three different papers, or the session devoted to understanding what your size 10 round does with a very wet load versus a nearly dry one. Reading about these materials is the preparation. The learning happens at the paper.
But being prepared — knowing why Arches hard sizing behaves differently from Fabriano's softer surface, knowing that your rinse water matters, knowing that the spring in a genuine Kolinsky is not a luxury but a functional property that enables a specific kind of mark — changes what you notice. And noticing is where painting begins.
A Practical Starting Point
For the student who has absorbed the pigment articles and is ready to assemble the full material practice:
Paper: Begin with Arches 140 lb (300 gsm) cold press in a block format. Learn this paper until you understand it before trying others. When you find it resisting something you want to do, that resistance will tell you what other surface to try next.
Water: Filtered or distilled in two clean jars. Change the clean jar frequently. Don't paint with brown water and expect luminous results.
Brushes: A quality synthetic round in sizes 8 and 10 for learning (the budget saved goes to better paper and paint). Add a genuine Kolinsky size 10 round when the synthetic's limitations become apparent to you — not before, because until you feel the difference from the painter's side, the comparison is meaningless. One squirrel mop for wetting and initial washes.
That is enough to begin. The rest accumulates with practice, with observation, and with the specific dissatisfactions that good materials produce — the awareness that something is possible which the current tool cannot quite achieve. That awareness is itself a sign of progress.
The paper is blank. The brush is clean. The water is clear.
Everything else is practice.
Next in this series: Mixing Darks, Neutrals, and Shadows — the painter's real curriculum, and why the most important colors are the ones you cannot buy.