Watercolor Granulation Medium: Does It Actually Work?

Granulating pigments are magical—they add depth and texture without any extra effort. But what happens when your favorite color simply doesn’t granulate?

That’s exactly the challenge Paint in Hiding faced with PB16 phthalo turquoise. It’s one of their absolute favorite colors, but sadly, it doesn’t granulate at all.

So when Paint in Hiding discovered Winsor & Newton’s Granulation Medium, they had to give it a try!

What Is Winsor & Newton Granulation Medium in Watercolor?

This medium is designed to add texture to watercolor paints, especially non-granulating ones. It helps pigments settle or clump together, creating the beautiful textured effects normally seen only in naturally granulating colors.

Why Use a Granulation Medium for Watercolor Painting?

The artist has always wished PB16 could behave like a granulating pigment. Cobalt turquoise offers a similar feel, but it appears too opaque and lacks strong tinting strength.

It even seems to contain a touch of white, which affects transparency and behavior. Because of this, the granulation medium became an ideal experiment.

Pigments Used to Test the Granulation Medium

For this test, the following pigments are used:

• Van Gogh Turquoise Blue — a mixture of PB15 (phthalo blue) and PG7 (phthalo green)
• Quinacridone Rose — made from PV19

Both pigments are transparent, highly staining, and non-granulating. That makes them perfect candidates for testing how effective the granulation medium truly is.

How to Use Winsor & Newton Granulation Medium: A Step-by-Step Test

The experiment begins with normal swatches, followed by swatches using the granulation medium.

Swatching Watercolor Paints Without Granulation Medium

The first swatches are painted using just water. They are:

• Clean
• Smooth
• Even in color

There is no texture or granulation—just flat washes. These swatches serve as the control sample.

Adding Winsor & Newton Granulation Medium to Watercolors

Next, the medium is added. A pipette is used to drop the medium directly into each paint pan. Following Winsor & Newton’s recommendation, a generous amount is applied.

The turquoise blue is tested first. Any accidental specks appearing in the mixture are simply due to handling, not the medium itself.

Then, the quinacridone rose is tested. Immediately, a reaction begins to appear…

The artist even adds more water below both swatches to see whether extra moisture helps the texture appear more strongly.

Mixing Watercolors with Granulation Medium for New Effects

After seeing some promising results, curiosity takes over. What happens when the two colors are mixed together with the medium?

Combining Colors to Explore Granulation and Texture

The granulated quinacridone rose is mixed into the turquoise blue—perhaps with a little too much turquoise—but the result is still revealing.

And suddenly, the granulation becomes dramatically visible. Strong texture forms, and even more flocculation appears. This is no longer simple color mixing; the pigment particles seem to “dance,” shifting and gathering in new patterns.

How Water Amount Affects Granulation Results

The test continues with increased water. With a lighter pigment load, the granulation becomes more pronounced.

Some swatches:

• Look super clear
• Contain fewer floating particles
• Show attractive color separation

Winsor & Newton Granulation Medium: Before and After Comparison

Once the swatches dry, it becomes easier to compare them closely.

Granulation Medium Effects on Dried Watercolor Paint

Most swatches are left to dry naturally, except for one puddle that is sped up with a hairdryer. The difference is noticeable.

The comparison begins:

• The clean control swatch
• The same pigment mixed with granulation medium

The difference is significant. Texture becomes visible where none existed before. Some areas resemble flocculation more than traditional granulation.

Granulation vs. Flocculation: What’s Really Happening?

Here’s the distinction:

• Granulation occurs when pigment settles naturally into the paper texture.
• Flocculation occurs when pigment particles clump together.

In these tests, the pigments show more clumping than settling—so technically, flocculation—but the visual effect is similar. Some swatches appear almost layered, with pigment collecting into dense patches.

With quinacridone rose, the granulated version dries to a matte, white-pink film, almost as if a filler has been added. This looks completely different from the clean, transparent wash in the untreated swatch.

Can Granulation Medium Be Pre-Mixed with Watercolor Paint?

A common question arises: can the granulation medium be mixed into the paint pan and allowed to dry for future use?

Testing Dried Pans with Granulation Medium Added

The medium is added to the paint pan and left to dry fully. After rewetting, the result becomes clear:

The pigment returns to its original non-granulating state.

The medium does not permanently alter the paint. It must be added fresh each time—no effective pre-mix shortcut.

Tips for Using Granulation Medium Effectively

Some artists apply the medium directly onto wet paint on the paper, creating striking textures. Others prefer mixing it on a ceramic palette for more control.

Is Winsor & Newton Granulation Medium Worth It?

So, after all that testing, how does the artist feel about it?

Pros and Cons of Granulation Medium in Watercolor Art

Although the results can be interesting, the artist is not completely satisfied. In many cases, the granulation medium causes excessive flocculation, leaving the paint slightly dirty or cloudy. This is far from ideal for anyone seeking clean, even watercolor washes.

However, that doesn’t mean the medium lacks value.

Best Uses for Granulation Medium in Watercolor Paintings

This medium can shine beautifully in specific contexts, especially in artworks that benefit from texture and natural irregularity. It works particularly well for:

• Abstract landscapes
• Rocky textures
• Natural scenes that need depth and variation

These applications allow the flocculation to enhance the artwork rather than distract from it.

The artist plans to explore the medium more in these scenarios and is curious to see how different pigments might respond. Some colors may pair better than the initial test pigments—there may even be a perfect combination waiting to be discovered.

Wrapping Up

Granulation medium is undeniably fun to experiment with. While it cannot transform a non-granulating pigment into a permanently granulating one, it provides an enjoyable way to add texture whenever needed.

For painters who enjoy exploring new effects and pigment behaviors, this medium is absolutely worth trying—just remember to use it fresh and keep experimenting with different watercolor pigments.