Watercolour possesses a certain magic, doesn’t it? Its transparency allows light to bounce off the paper, creating luminous washes and delicate transitions. It’s the medium of suggestion, atmosphere, and glowing light. Then there’s gouache, its close cousin, but with a personality all its own. Opaque, velvety, and bold, gouache offers coverage, flat colour blocks, and the ability to lay light tones over dark ones. Standing alone, each paint is powerful. But bring them together? That’s where a whole new world of creative possibilities opens up in mixed media art.
Combining watercolour and gouache isn’t about choosing one over the other; it’s about leveraging the unique strengths of both to achieve results neither could easily produce alone. Think of it as a partnership where transparency meets opacity, subtlety meets boldness, and light meets substance.
Understanding the Players: Watercolour vs. Gouache
Before diving into techniques, let’s quickly recap what makes each medium distinct. Understanding their core properties is key to using them effectively together.
Watercolour: The Transparent Luminary
Traditional watercolour relies on pigments suspended in a binder (usually gum arabic) that becomes transparent when water is added. The key characteristics include:
- Transparency: This is its defining feature. Colours are layered optically, meaning light passes through the paint layers, reflects off the white paper, and comes back through the colours. This creates luminosity.
- Flow and Blending: Watercolour loves to move with water, making it ideal for soft edges, gradients, and atmospheric washes.
- Layering: You build richness by layering washes, typically working from light to dark. Subsequent layers modify the ones beneath without completely obscuring them.
- Lifting: Depending on the pigment and paper, you can often lift (remove) colour while it’s wet or even after it’s dry, though some pigments stain more than others.
- Paper Dependence: The white of the paper is crucial, acting as the brightest white in the painting.
Gouache: The Opaque Powerhouse
Gouache also uses pigments and gum arabic, but it contains higher pigment loads and often includes white fillers (like chalk) to make it opaque. Its main traits are:
- Opacity: This is its superpower. Gouache can cover underlying layers, including dark colours or mistakes. Lights can be painted over darks.
- Matte Finish: When dry, gouache typically has a flat, velvety, non-reflective finish.
- Re-wettable: Like watercolour, dried gouache can be reactivated with water. This is useful for blending but can be tricky if you’re layering heavily, as the underlying layer might lift.
- Bold Colour: Due to its opacity and pigment load, gouache offers strong, vibrant colour straight from the tube or with minimal water.
- Consistency Control: It can be thinned with water to become more translucent (though not truly like watercolour) or used more thickly for impasto-like effects.
Why Bring Them Together? The Synergistic Benefits
Combining these two seemingly different paints unlocks a host of advantages:
- Enhanced Contrast and Depth: Use watercolour’s transparency for soft backgrounds, skies, or distant elements, then bring in opaque gouache for crisp foreground details, subjects, or focal points. This juxtaposition creates a powerful sense of depth.
- Adding Highlights and Details: This is perhaps the most common reason. Struggling to preserve the white of the paper for highlights in watercolour? No problem. Let your watercolour layer dry, then pop in brilliant highlights or fine details (like light glinting off water, tiny flowers, or starshine) using opaque white or coloured gouache.
- Correcting or Adjusting: Made a mistake in your watercolour layer that you can’t lift? A carefully applied layer of gouache in the right colour can often cover it up discreetly. It’s more forgiving than pure watercolour.
- Achieving Unique Textures: You can scumble thick gouache over a smooth watercolour wash for textural contrast, or thin gouache slightly and let it mingle wet-into-wet with watercolour for semi-opaque effects.
- Speed and Efficiency: Sometimes, quickly blocking in a solid shape with gouache is faster than building up the same value and opacity with multiple watercolour layers.
- Expanding the Value Range: Gouache makes achieving very dark, flat areas or very bright, opaque highlights much easier than watercolour alone.
Techniques for Harmonious Combination
There’s no single “right” way to combine watercolour and gouache, but here are some common and effective approaches:
Watercolour First, Gouache Details Last
This is the most intuitive method for many artists. Start by laying down your watercolour washes, establishing the overall mood, light, and base colours. Let everything dry completely – and this is crucial. Then, use gouache (often slightly thicker than you might use watercolour) to add:
- Opaque highlights: White or light-coloured details on top of darker areas.
- Sharp details: Fine lines, patterns, textures, or elements that need to stand out clearly.
- Solid colour blocks: Defining shapes or areas that need strong, flat colour.
- Corrections: Covering unwanted marks or refining edges.
Gouache Underpainting (More Experimental)
While less common, you could block in shapes or tones with gouache first. Once dry, you could apply transparent watercolour washes over it. The gouache might lift slightly if overworked, creating interesting textures, or it might act as a coloured ground peeking through the watercolour. This requires careful water control.
Mixing Watercolour and Gouache
You can physically mix the two paints on your palette. Doing so essentially creates a semi-opaque paint. Adding a little white gouache to watercolour can make it slightly chalkier and more pastel-like, increasing its covering power. Mixing coloured gouache with watercolour can yield interesting hues with partial opacity. Be mindful that this reduces watercolour’s transparency and gouache’s full opacity.
Wet-into-Wet Play
Applying gouache into a still-wet watercolour wash (or vice versa) allows the paints to mingle directly on the paper. Gouache, being heavier, might push the watercolour aside or blend in soft, cloudy ways. This can create beautiful, unpredictable effects, especially for atmospheric skies or watery scenes, but requires practice to control.
Dry Brushing and Scumbling
Load a brush with gouache, remove most of the moisture on a paper towel, and then lightly drag or scrub the brush over a dry watercolour layer. This deposits broken colour, creating texture perfect for depicting foliage, rough surfaces, or adding subtle tonal variations.
Patience is paramount when layering these mediums. Ensure your watercolour layers are absolutely bone dry before applying gouache on top. Applying gouache to damp watercolour can lead to muddy colours, unwanted lifting, and frustration. Similarly, let gouache layers dry before adding subsequent watercolour washes if attempting more experimental techniques.
Choosing Your Materials
The good news is that if you already have watercolour supplies, you’re mostly set.
- Paper: This is critical. Because you’ll likely be using multiple layers of water-based media, choose a robust paper. 300gsm (140lb) watercolour paper is generally recommended as a minimum. Cold press offers some texture, which works well with both mediums, while rough paper provides even more texture. Hot press (smooth) paper can also be used, especially for detailed work, but shows washes differently.
- Paints: Use your preferred watercolours. For gouache, consider starting with a basic set or at least a tube of permanent white gouache, as this is invaluable for highlights. Artist-grade paints in both mediums generally offer better pigment load and lightfastness.
- Brushes: Your standard watercolour brushes (rounds, flats, mops) will work perfectly well for both. You might want a few small, perhaps synthetic, round brushes dedicated to fine gouache details, as gouache can be a bit harder on delicate natural hair brushes over time.
- Palette: A simple ceramic or plastic palette works for both. Remember that gouache dries opaque and might need scrubbing to clean fully once dried, whereas watercolour often lifts more easily.
A Simple Exercise: Landscape Enhancement
Try this to get a feel for the process:
- Sketch: Lightly sketch a simple landscape – perhaps hills, a sky, and a simple tree or building.
- Watercolour Base: Apply watercolour washes for the sky (maybe a soft blue gradient) and the land (greens, browns). Let these layers dry completely. You can add some watercolour details like distant trees or cloud shadows. Let dry again.
- Gouache Foreground: Mix a nice opaque green or brown gouache. Paint the main tree trunk and branches, or the solid shape of the building. Notice how it sits crisply on top of the watercolour background.
- Gouache Highlights: Use white gouache (or a light tint) to add highlights. Perhaps some light catching the edge of the tree leaves, a glint on a window, or bright wildflowers in the foreground grass. Use it sparingly but decisively.
- Refine: Look at your piece. Are there any areas that need darkening or more definition? Opaque gouache can help refine edges or add small shadows.
Embracing the Possibilities
The true beauty of combining watercolour and gouache lies in the expanded range of expression it offers. Illustrators often rely heavily on this combination – think of the crisp characters against soft backgrounds in children’s books, or the detailed botanical studies where opaque veins stand out on translucent petals. Concept artists use it to quickly block in forms and add lighting effects. Fine artists leverage the textural and tonal contrasts for unique atmospheric pieces.
Don’t be afraid to experiment. See what happens when you glaze thin watercolour over dry gouache. Try using gouache resist techniques. Use stencils with thick gouache over a delicate wash. The rules aren’t rigid; the goal is to find combinations that help you achieve your artistic vision. By understanding the individual strengths of transparent watercolour and opaque gouache, you can make them work together, creating artworks that possess both luminosity and substance, delicacy and strength.
