The history and chemical composition of water-soluble pencils

Watercolor pencils appeared on the art market in the 1940s. Engineers sought to create a portable tool for outdoor work. The new invention combined the properties of dry pastel, graphite, and classic liquid paint. The pencil’s lead reacts actively to the addition of water. The moisture instantly dissolves the binder within the colored pencil. The pigment is released, forming an even layer of paint on the paper surface.

Artists gain the ability to combine precise graphics with soft, painterly washes. The fine tip of the brush perfectly captures the finest details of small objects. A damp brush quickly transforms sharp strokes into smooth color transitions. This process requires strict moisture control. Too much water blurs the drawn contours too much, while too little fluid leaves a noticeable texture of the original stroke.

Evolution of binders

The secret to water solubility lies in the chemical composition of the binder. Factories often use gum arabic, a natural resin from the acacia senegal tree. Gum arabic reliably holds the fine particles of colored powder together. Polyethylene glycol is sometimes used as an alternative. This synthetic, water-soluble compound ensures the lead glides very smoothly over rough paper.

The formula for the rod consists of pigment, a binder, special lubricants, and mineral fillers. Kaolin or regular talc serve as fillers. The mixture is kneaded, formed into thin, long cylinders, and dried under a strict temperature regime. The diameter of the finished rod is typically about 3 millimeters.

The process of making wooden cases

The finished, fragile lead is placed in a wooden case to protect it from mechanical damage. Manufacturers prefer California cedar for its softness and even grain. The wooden blanks are cut into thin planks with longitudinal grooves. The lead is placed in these grooves.

A second wooden plate is glued on top, creating a kind of sandwich. After the glue dries, milling machines cut the block into individual hexagonal or round pencils. The body is coated with several layers of varnish, the color of which precisely matches the shade of the inner core. The wooden shell protects the artist’s hands from accidental staining by the concentrated pigment.

Auxiliary materials and tools

The successful application of this technique directly depends on the choice of supporting materials. Regular office paper quickly warps when wet. Painting requires a special support that can withstand intense moisture and strong mechanical abrasion. The paper must maintain its flat shape after puddles of water have dried.

The effect of sizing on paper absorbency

Watercolor paper with a thickness of at least 300 g/m² is suitable for this work. This thickness prevents excessive warping when wet. Lighter sheets, such as 185 g/m², require pre-stretching on a wooden board. Watercolor paper undergoes a sizing process during production.

Traditionally, factories use natural gelatin to size sheets. Modern brands replace animal gelatin with synthetic alternatives such as methylcellulose. Sizing prevents the paper from acting like a sponge. It holds the pigment to the surface, preserving maximum vibrancy and color saturation. Cotton fibers deeply absorb moisture, creating soft edges for washes. Cellulose allows for easy removal of unsuccessful paint layers with a stiff brush.

Anatomy of hands with reservoir

Blending strokes is achieved with various types of brushes. Artists often choose natural brushes made from squirrel or kolinsky hair. Squirrel hair absorbs a huge amount of water and releases it evenly. Kolinsky hair is characterized by increased elasticity and allows for good control of the direction of each stroke.

Synthetic brushes are very stiff. They effectively dissolve dense layers of pencil pigment on paper. Brushes with a water reservoir have become particularly popular. A reservoir of liquid is stored inside the plastic handle, gradually releasing it into the synthetic bristles. This eliminates the need for the artist to constantly dip the brush in a jar of water. This tool is ideal for working outdoors.

Basic pigment application techniques

There are several basic algorithms for working with water-soluble rods. Each method produces a specific visual result. Artists often combine these approaches within a single composition to create contrasting textures.

Dry hatching with subsequent activation

This is the most common method of creating images. First, the artist draws with a dry tool on completely dry paper. Hatching is applied in dense layers. Lighter shades are overlaid with darker ones. Different colors are superimposed on each other in a cross-hatch pattern or uniform spots.

After completing a dry drawing, apply a damp brush. Water immediately activates the pigment, blending the applied layers of hatching. New complex shades and very smooth color transitions are created. The color intensity is visually enhanced several times after wetting. The direction of the brush strokes should strictly follow the shape of the object being depicted. The brush should be rinsed periodically to avoid dirty gray spots when mixing opposing colors.

Wet paper method

The wet-on-wet technique creates vibrant, highly saturated lines with very soft edges. The artist first generously wets a sheet of paper with clean water. Then, using a dry pen, precise strokes are applied directly onto the wet puddle. The concentrated pigment dissolves instantly upon physical contact with water.

The resulting line is thick, velvety, and opaque. The edges of the strokes quickly blur, creating a fluffy, colored outline. This method requires quick and confident strokes while the paper remains damp. Pressing hard on the tip can scratch or completely tear the soggy top layer of paper. This method is often used to create expressive accents in the very foreground of a painting.

Specific techniques and textural effects

Pencils can be used for purposes far beyond their intended graphic purpose. Colored lead serves as a very compact source of highly concentrated paint. These unconventional methods significantly expand the artist’s arsenal of available techniques.

Direct paint application from the pencil lead

The artist takes a well-wetted brush and vigorously draws it across the pencil tip. The brush bristles pick up the thick, dissolved pigment directly from the core. This colored solution is then transferred to the paper using traditional, broad watercolor brushstrokes.

This method produces absolutely pure, transparent washes without the slightest trace of pencil shading. The intensity of the color tone can be easily adjusted by varying the amount of water on the synthetic bristles. This technique is very useful for quickly painting large areas of a drawing, such as the sky or seawater. Loading paint directly from the pencil saves the artist time and prevents unwanted harsh lines from appearing in the background.

Mechanical scraping of pigment

Special textures are created by deliberately grinding the colored lead mechanically. The artist generously wets the desired area of the paper with clean water. Then, using a sharp craft knife or a piece of coarse sandpaper, the dry lead is vigorously scraped directly over the wet area of the drawing.

Small colored crumbs fall onto a water lens and instantly dissolve, creating a chaotic scattering of bright dots and contrasting color spots. The size of the specks directly depends on the degree of grinding of the hard core. Fine colored dust creates the illusion of thick fog or a sandy shore. Large chipped particles imitate tree foliage, the texture of stones, or fine splashes of water. After the paper has completely dried, any remaining dry dust is blown off or gently brushed off with a large, soft brush.

Application of masking fluid

To preserve the pure white areas of the paper, artists use a liquid mask. This is a special compound based on natural or synthetic latex. The mask is applied with a thin brush to the areas that should remain unpainted. After drying, the liquid turns into a thick, rubbery film.

Once the film has dried, you can confidently apply hatching and wash it away with plenty of water. The rubber reliably repels water and pigment from the paper fibers. After the paint layer has completely dried, simply erase the mask with your finger or a regular eraser. The removed film leaves behind a clean, white, perfectly formed piece of paper.

Peculiarities of working outdoors

Painting outdoors requires a special workflow. Pencils are ideal for travel due to the absence of liquid paints in the palette. The tools take up minimal space in a backpack or travel bag. There’s absolutely no risk of spilling colored liquid on clothing or documents.

Wind and direct sunlight accelerate the drying process of paper outdoors. Rapid evaporation of moisture forces the artist to work at an accelerated pace. Large washes of sky or grass dry out before the artist can add the desired color nuances. Using brushes with a water reservoir partially solves this problem. A constant supply of fresh water from the plastic handle moistens the working area of the paper. Artists often carry small spray bottles to quickly wet the entire sheet.

Temperature restrictions

The materials are highly sensitive to ambient temperature. Freezing weather precludes the use of water to blur lines. Drops of moisture freeze on the paper’s surface, destroying the top layer of sizing with sharp ice crystals. In winter, artists only perform the dry graphic portion of their work. Pigment activation with water occurs later in a warm studio.

Extreme heat also negatively affects pencils. The synthetic binders inside the lead soften at high temperatures. The lead becomes excessively pliable and breaks quickly when pressed hard against the paper. The pigment leaves unnaturally thick, dense lines. Pencils should be kept out of direct sunlight in closed cases. A wooden barrel protects the lead from completely melting, but the lead itself requires careful handling during the summer months.

Integration with other artistic materials

Mixed media create unique visual effects. Watercolor pencils blend seamlessly with classic water-based media. The pencil leads adhere well to the dried stains of traditional watercolor from pans. Pencil strokes add definition and texture over soft background washes.

Using mascara and eyeliner

Graphic elements are often drawn with waterproof materials. Fineliners, liners, and alcohol markers provide an excellent base for subsequent work. The artist first creates a detailed outline drawing with waterproof ink. The ink penetrates deeply into the pores of the paper and dries instantly.

Dry pencil hatching is then applied over the black lines. A wet brush dissolves the colored pigment but leaves the ink outlines completely intact. Waterproof liner shows through the transparent layers of watercolor. Using non-waterproof ink will lead to disastrous results. The water will mix the black paint with the colored pigments, creating muddy streaks all over the page.

Combination with dry pastel

Leads are a great complement to dry pastel works. Pastel leaves a thick layer of paint dust on the paper. Pencils cut through this layer, creating subtle graphic accents. Water wash is rarely used in this case.

Mixing wet watercolor pigment with the chalky dust of pastel produces a muddy and unpredictable result. The materials are usually used strictly separately in different areas of a single painting. Pencils refine fine details of faces or patterns. Pastel covers large areas of the background with soft, velvety patches. Differences in the chemical composition of the materials require the use of special aerosol fixatives to seal the final result.

Multi-layered painting and graphic accents

Complex paintings always require the successive application of multiple layers of paint. Watercolor pencils are excellent for this task, provided strict technical discipline is observed. Layers are applied sequentially, very carefully, and with adequate drying time.

The first base layer is usually applied with light, sparse hatching and completely washed with water. This initial stage establishes the overall light and color scheme of the entire painting. The drawing must be completely dry before applying the next graphic layer. Attempting to apply heavy hatching on half-wet paper will inevitably result in dirty grooves and a complete destruction of the paper’s texture.

Each subsequent dry layer adds the necessary detail and color saturation to the drawing. Artists successively apply up to five or six layers of concentrated pigment. The very last fine details are often drawn on a completely dry background without any subsequent washing. A sharp dry pencil over a transparent watercolor wash creates crisp, clear contours. This contrast between soft, washed-out spots and sharp, dry lines gives the flat image a deep visual volume.

Preservation and archiving of completed works

Graphic works require special climatic storage conditions. The binder in the lead remains permanently water-soluble, even years after the drawing has completely dried. A few stray drops of water will instantly ruin the finished work beyond repair.

Finished paintings must be framed under regular or anti-reflective glass. A glass screen reliably protects the paper surface from seasonal humidity, household dust, and direct mechanical damage. Using a frame made of very thick cardboard guarantees that the paper does not come into physical contact with the glass. An air gap inside the frame eliminates the risk of harmful condensation and subsequent pigment adhesion to the transparent glass.

Lightfastness testing

The lightfastness of the strokes directly depends on the chemical quality of the pigments used at the factory. Professional series of art materials contain pigments with a high degree of resistance to aggressive ultraviolet light. Manufacturers regularly test their products under strict laboratory conditions.

The standardized Blue Wool Scale is often used to assess color fading rates. Paint samples are exposed to intense light, along with reference wool strips dyed with blue dye. A rating of eight on this scale indicates the highest color fastness. Colors with a rating below three fade quickly under room lighting. Designs should be hung on walls protected from direct, intense sunlight.

Surface and grades of paper

When choosing a paper brand, it’s more useful to look at the density, fiber composition, and sizing type than the series name or price of the sheet, as these parameters determine how water and pigment behave on the surface. Watercolor pencils typically use paper of around 300 g/m² (11 lb) thickness, as this type of sheet holds moisture significantly better and is less prone to warping. Thinner sheets, such as those around 185 g/m² (6 lb) thickness, often need to be pre-stretched onto a drawing board.

Cotton paper typically produces a soft stain edge and a more subdued tonal transition, while cellulose paper often tolerates washes and partial surface corrections better. Sizing holds the dissolved pigment closer to the top layer of the sheet, resulting in a purer color and less discoloration. Some modern papers use synthetic sizing, while traditional mills long relied on gelatin sizing.

Each brand has its own signature, but it’s best to look at a test brushstroke. The same green behaves differently on different sheets: on a smooth background, it lays more evenly, on grain, it fragments, and on soft cotton, it produces a calm haze. Therefore, artists often buy one sheet from each series and do a short test before starting a large work.

Checking the sheet before work

The simplest test takes a couple of minutes. Apply two thick strokes to a dry area, then blend one with a nearly dry brush and the other with a brush with plenty of water. If the color remains clear, the paper doesn’t fray, and the edge of the stain is controllable, the sheet is suitable for multi-layer work.

It’s worth checking your eraser, too. Some sheets hold dry correction easily, while others quickly lose their top layer. With a watercolor pencil, this is immediately noticeable: after re-hatching the damaged area, the color lays unevenly and catches on the bristles.

Mixing shades of green

Green in watercolor pencils rarely looks convincing when applied directly from a single pencil. Typically, a vibrant shade is composed of yellow and blue, then shifted toward warm or cool. If you’re aiming for the color of young foliage, use a warm yellow and a pure, cool blue. For pine needles or shadows, use a cooler yellow, a deep blue, and just a touch of earthy tones.

A good green is almost always built through temperature differences. A warm base creates a sense of light, while a cooler base adds structure and density to the mass. If an entire area is painted with a single, ready-made green, the surface often appears dull, airless, and lacking depth.

When mixing, it’s helpful to work in layers rather than applying a single, heavy stain. First, apply a light yellow layer, then add blue, then activate a small section with water and observe the result. This order helps prevent premature dirt buildup and gives you room for adjustment.

Patterns for grass, foliage and needles

For grass in the light, a combination of lemon yellow, medium blue, and a touch of ochre works well. If midday light is desired, more yellow is added to the upper planes, and a touch of cool blue to the lower ones. When the finish is dry, individual stems can be easily touched up with a sharp olive or dark green pencil, without water.

For tree foliage, it’s best to use three mixtures at once. The first is light and warm for the upper planes of the canopy. The second is a neutral medium for the main mass. The third is muted, with a touch of reddish-brown or purple, for the shadows between the leaves. This prevents the green from breaking up into a random collection of spots and helps maintain its volumetric form.

For coniferous trees, pure, bright green is almost always too garish. A mixture of dark blue, yellow-green, and a very small amount of warm brown comes to the rescue. The brown counteracts the acidity, while the blue condenses the mass into a dense, cool tone.

When green is too toxic, don’t immediately kill it with black. Black often makes a color look dead and muddy. A small addition of a complementary red, burgundy, or red-brown works more subtly. This approach reduces the harshness of the tone without depriving it of its inner life.

Water and edge control

The main difficulty with watercolor pencil isn’t the stroke, but the amount of water applied. A brush that’s too wet instantly blurs the distinctions between layers and spreads pigment across the paper. A brush that’s too dry leaves streaks that no longer read as painting or look like graphic art. That’s why many people keep two brushes close by: one for activating the brush and one for drying the edges.

It’s convenient to divide a stain’s edge into three types. A hard edge is needed where the shape sharply separates from its neighbors. A soft edge is suitable for penumbra and distant views. A jagged edge is useful for tree crowns, stone, and old plaster. When the artist consciously varies these types as the work progresses, the drawing begins to sound clearer.

On paper with a pronounced sizing, water stays on the surface longer, and the color is easier to move with a brush across the sheet. On a more absorbent base, the transition sets faster and is more difficult to correct. For this reason, the same technique on different grades of paper produces different results, even with the same pigment.

There’s also a simple technique for creating a clean edge. First, activate the color within the form, then use a washed, semi-dry brush to remove excess moisture along the edge. This will stop the edge from creeping. This technique is especially useful in botanical work, where you need to maintain the outline of a leaf, petal, or thin branch.

Sharpening, erasing and straightening

Watercolor pencils require more careful sharpening than regular colored pencils. Water-soluble pencil leads are often softer and more prone to crumbling, especially if they contain a lot of pigment and a soft binder. A tip that’s too long and thin breaks easily, while a short, blunt tip doesn’t produce precise lines on a dry surface.

Many artists sharpen their pencils with a knife, leaving a short, strong point. This is even more convenient for broad fills: the side of the lead quickly fills the area, while the tip is used for veins, fine highlights, and edge accents. If you need a very fine graphic trace, it’s wise to dry the paper completely first and only then go over the details with a dry lead.

An eraser has limited effectiveness here. On dry paper, it removes some pigment, but after activation with water, the color penetrates the top layer of the sheet and is more difficult to remove. On cellulose paper, you can gently lift some of the pigment with a damp brush or cloth, but on soft cotton, rough work quickly damages the surface. Therefore, it’s best to plan out highlights in advance or cover them with a liquid mask before the first washes.

Common mistakes

One of the most common mistakes is trying to build saturation with one thick layer and too much water. The result is a sticky stain with no internal structure. Two or three light passes, allowing them to dry completely between each, produce a much cleaner result.

Another mistake is mixing too many pigments in one small area. This is especially noticeable with greens. If yellow, blue, ready-to-use green, ochre, and black meet in one spot, the color will almost certainly turn into a muddy gray-brown. It’s better to keep the palette short and create distinctions through pressure, dry strokes, and the amount of water.

Another mistake is related to storage. Dried work remains sensitive to moisture because the binder in these pencils remains water-soluble. For this reason, sheets are kept under glass or in dry, lined folders, preventing the painted surface from coming into contact with the adjacent sheet.

Working diagram for a botanical sketch

For a botanical motif, it’s convenient to start with a light line drawing using a hard, light pencil. Then, outline the main masses with yellow-green and ochre tones, avoiding the lightest veins. The first wash is done with a moderately damp brush, without trying to achieve the final color right away.

After drying, cool greens are added to the shadows and subtle blue or purple accents where the leaf meets the light. At this stage, it’s already clear which areas look too flat. These aren’t darkened with black, but rather are controlled by temperature — warmer in some places, cooler in others, and drier at the edges.

The final touch is created with dry strokes. Veins, nicks, leaf edges, insect marks, and tiny mold spots are easier to achieve without water, using a sharp point on dry paper. This way, the drawing retains its vibrant materiality and doesn’t blur into an overall soft layer.