Chris Breier “Sunlit Church” Watercolor on Arches rough 8″x10″

The grainy look isn’t necessarily a bad thing in a watercolor painting. In fact, I often choose pigments that are granulating so that I can create interesting textures in my paintings. However, some subjects don’t benefit from granulating colors. Glass objects, for example, may look more realistic if you use pigments that are more transparent and smooth.

Why do my watercolor paintings look grainy? Some pigments are naturally granulating which means they’re coarser and have a tendency to clump together as they dry. The texture of the paper can accentuate this effect. Rough watercolor paper can have a pebbly surface that you may interpret as grainy. Lastly, if you overwork the paper, it can disintegrate and begin to look fuzzy.

In this post, I explain how your choice of pigments and paper can make your watercolor paintings appear grainy or smooth. Once you understand how these variables affect the painting, you will have more control over the appearance of your watercolors. I also cover causes other than granulation that may be making your watercolor paintings look grainy.

Granulating Pigments Create Grainy Washes

The pigments that watercolor paints contain come from a variety of sources. Some of them are minerals and these are the inorganic pigments. Inorganic pigments have a tendency to granulate as they dry, which is what can create a mottled appearance.

Organic pigments, also known as “modern pigments,” are derived from chemicals in a lab. They’re usually more transparent and dry with a smooth appearance.

An example of granulating watercolor pigments.
Here is a color chart of the granulating pigments that I have in my studio. These are QoR watercolors on Arches rough watercolor paper. Painting with the paper at an angle helps to make the colors granulate, especially if you use more water and allow it to run down the paper.

Watercolor Color Charts

So, now that we know it’s the granulating pigments that create the speckled watercolor look, we can then identify which colors are responsible for this. Below is a list of links to the color charts from the most common brands of watercolor. They all identify which pigments are granulating. This will save you from having to conduct your own tests.

Watercolor Paint Color Charts
Daniel Smith
M Graham Watercolors
Golden – Qor watercolors
Winsor & Newton Cotman (student)
Winsor & Newton Professional

Please note that one manufacturer may identify a color as granulating while another may not. For example, Golden lists Burnt Sienna as a granulating color, but Winsor & Newton does not. This is because they use different pigments to make Burnt Sienna. They both have the Burnt Sienna name, but they contain different pigments.

Golden uses calcined natural iron oxide for their Burnt Sienna and they list it as granulating. Winsor & Newton uses transparent synthetic iron oxide for Burnt Sienna and it doesn’t granulate.

Another issue is if you’re using student grade watercolors that contain substitute pigments, they may have different characteristics than the original pigments they’re named after. You can refer to the color charts for your brand of watercolor paint to determine which colors are granulating. The color charts for the top brands of watercolor paint are above.

What Causes Pigments to Granulate?

Winsor & Newton makes a distinction between pigments that clump together and pigments that settle into the texture of the paper. They state in their color chart, that I link to in the table above, that flocculation is when the pigments clump together. This effect can happen even on smooth paper. Cerulean Blue is a pigment known for this. Granulation is when the pigments settle into the texture of the paper.

Sometimes I notice artists use the terms interchangeably as if they mean the same. Granulation is generally used to describe both effects. What’s important here is to notice that those are the two ways that your watercolors can become grainy. If you understand both effects, you can have more control over the results.

Winsor & Newton also claim that using distilled water may help to reduce granulation, especially if you live in area that has hard water. This information is also in their color chart.

Using a lot of water in my washes seems to encourage granulation, especially if the paper is at an angle.

This leads me to my next point, which is the paper has an impact upon the appearance of your painting.

How the Paper Can Make Your Paintings Look Grainy

In addition to granulating pigments, the texture of your paper can influence how your painting looks. If someone asks me why their painting looks grainy, I first have to determine if they’re referring to the paper texture or the granulation of the pigments.

Sometimes it’s the paper. Perhaps you’re expecting your watercolors to have a smooth look, but the bumpy texture of the paper gives it a course look that you may describe as “grainy.”

Watercolor Paper Textures

When you light the painting from above, it can accentuate the texture of the paper further. This can be distracting, especially if the painting consists of subtle colors and values.

This painting is on Arches rough. I took this photo with the lighting directly above the painting.

I took this photo with the lighting directly above the paper. This type of uneven lighting will exaggerate the texture of the watercolor paper. If that’s what you mean by “grainy,” then you should experiment with different types of paper. If the texture is only visible in the photograph of your painting, then it’s probably your lighting. Here’s how the same painting of row boats looks with even lighting.

For more tips, you may want to read my in depth post how to photograph art

Watercolor paper is available in 3 types of textures: Hot press, Cold press, and Rough. Fabriano also makes “soft press” watercolor paper, but that’s more of an exception.

Hot press is the smoothest of them all, so you may want to try it out if you prefer smooth watercolor paintings. If you find that it’s too smooth, then cold press has a subtle texture to it.

I should also stress that different manufacturers produce papers with different kinds of texture. Fabriano cold press looks entirely different than Arches cold press. Unfortunately, the only way to figure out which paper you like the most is to try them out for yourself.

Pilling Can Be the Cause of Fuzzy Watercolor Paintings

An example of pilling in watercolor painting.
The bottom swatch of Ultramarine Blue contains “pilling.” I scrubbed the bottom sample with the brush. That fuzzy look is the paper disintegrating.

“Pilling” is when you overwork the paper and it starts to disintegrate. Brushing over the same spot can cause the fibers of the paper to pull up from the surface and gives the painting a fuzzy look. Perhaps this is the source of your grainy watercolors if the none of the other explanations seem to fit.

Usually, it’s the less expensive paper that will do this when you overwork it. Watercolor paper is generally 100% cotton and it contains sizing so you can work it more than the inexpensive brands.

The more expensive brand names of watercolor paper can take more abuse, but they also have their limits. Scrubbing the surface of the paper with a stiff brush will cause pilling, even in the quality watercolor papers.

Drawing paper is known for pilling when you paint on it with watercolor. It has others disadvantages as I discuss at length in my post about using drawing paper for watercolor.

Watercolor brushes have softer bristles than the brushes that you use for oils or acrylics. The stiffer bristles can disturb the fibers of the paper, so make sure your using paint brushes made for watercolor.

Examples of Granulation in a Watercolor Painting

My painting “Sunlit Church,” at the top of this post, contains some granulation. Most of the granulation is in the darker colors in the trees above the church. The yellow green was painted first and allowed to dry. Then I used Ultramarine Blue to make a darker green and painted over the light green. This darker green granulates because of the ultramarine Blue, and it allows the lighter green to show through.

You can watch me paint Sunlit Church on Youtube.

Below is an example of a sky that contains some granulation. I like to use Cerulean Blue for painting skies. If you don’t like the granulation in the sky, you can use a blue that’s not a granulating color, such as Phthalo Blue. As a result, it will dry with a much smoother appearance.

A watercolor painting that contains granulation in the sky.
Chris Breier
“Heat Wave”
Watercolor on Arches rough

Related Questions

What watercolors are opaque? Gouache, which is pronounced “gwash,” is opaque watercolor. It behaves in a manner that’s similar to watercolor except that it’s opaque enough to cover over mistakes. Some watercolor artists use white gouache to add small highlights to their transparent watercolor paintings.

If you’re wondering about the opacity of transparent watercolors, it varies depending upon the pigment. Watercolor manufacturers list the opacity of each pigment on their color chart. The opacity can sometimes be found on the label on the tube of paint itself.

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