You can make watercolor paint opaque primarily by adjusting the ratio of pigment to binder and water, creating a mixture with a higher pigment load and a thicker consistency than traditional transparent watercolors.
Understanding Watercolor Opacity
Traditional watercolor is known for its transparency, allowing light to reflect off the paper surface and back through the pigment layers. Opacity, in contrast, refers to the paint's ability to cover the underlying surface, blocking light from passing through. Achieving opacity with watercolor means creating a paint that sits on the surface rather than soaking into it transparently.
The Core Method: Pigment, Gum Arabic, and Water
The most direct way to create opaque watercolor from scratch involves carefully mixing the raw ingredients. As stated in the reference, by mixing pigments with gum arabic and water, an artist can create a thicker and more opaque paint than traditional watercolors.
Why This Mix Works
- Higher Pigment Load: The key difference is using a significantly higher concentration of pigment relative to the binder (gum arabic) and water. More pigment particles packed together inherently block more light.
- Thicker Binder: Gum arabic acts as the binder, holding the pigment together. By using less water relative to the gum arabic solution and pigment, the resulting paint has a thicker consistency. This thicker vehicle ensures the pigment stays suspended densely and applies as a solid layer rather than a thin, transparent wash.
Essentially, you are creating a paint where the pigment particles are so dense and the medium is so thick that light cannot easily pass through the dried layer.
Practical Steps for Creating Opaque Watercolor
If you are starting with raw pigments, here's how you can apply the principle:
- Gather Your Ingredients: You'll need pigment powder, a gum arabic solution (gum arabic dissolved in water), and additional water.
- Start with Pigment: Place the desired amount of pigment powder onto a mixing surface (like a glass muller and slab or a palette).
- Add Gum Arabic Solution: Gradually add small amounts of the gum arabic solution to the pigment.
- Add Water (Sparingly): Add just enough water to help the mixture become a smooth paste. The goal is a thick consistency, not a watery wash.
- Mix Thoroughly: Grind the mixture with a muller or mix vigorously with a palette knife or brush until all pigment particles are fully dispersed in the binder, creating a smooth, thick paste.
- Test Opacity: Apply a swatch on paper, preferably over a dried line or color, to see how well it covers.
- Adjust: If it's too transparent, add more pigment powder. If it's too thick or difficult to work, add a tiny amount more water or gum arabic solution.
The exact ratios will depend heavily on the specific pigment used, as some pigments require more or less binder.
Alternative Approaches for Achieving Opaque Effects
While mixing pigment, gum arabic, and water with specific ratios is the fundamental way to create opaque watercolor, artists also achieve opaque effects in watercolor paintings using other methods:
- Using Naturally Opaque Pigments: Some pigments are inherently more opaque than others, even in a standard watercolor formulation. Examples include Cadmium colors, Cobalt colors, Titanium White, and many earth pigments. Choosing paints made with these pigments can provide more opacity straight from the tube or pan.
- Mixing with Opaque White: Adding an opaque white watercolor (usually containing Titanium White) to a transparent color is a common way to make it more opaque and create pastel shades.
- Using Gouache: Gouache is essentially opaque watercolor. It uses a higher pigment concentration and often contains an added white filler (like chalk) to increase opacity. Using gouache is another direct way to incorporate opaque elements into a watercolor painting.
Comparing Transparent vs. Opaque Approaches
Here's a simple comparison highlighting the difference achieved by adjusting the mixture as described:
| Feature | Traditional Transparent Watercolor | Opaque Watercolor (Mixed Thick) |
|---|---|---|
| Opacity | High transparency, light passes through | Low transparency, covers underlying layers |
| Pigment Load | Lower ratio of pigment to binder/water | Higher ratio of pigment to binder/water |
| Texture | Often flows smoothly, thin washes | Thicker, potentially more brush texture |
| Application | Layering, glazing, washes | Flat color, covering, details, highlights |
By understanding the relationship between pigment, binder (gum arabic), and water, you can control the opacity of your watercolor paints.
