Adding Glycerin to Gouache (why and how)

If you are a gouache lover, then you must know it dries quickly. The feature is particularly advantageous for creating multiple layers within a short time. After one layer dries, one can put another layer without any fear of color blending. But sometimes, gouache colors dry even in the color tray or brush before you apply them to the canvas, which is frustrating. Therefore, many artists add Glycerin to Gouache paints. Why do they do this?

Adding Glycerin to Gouache
Adding Glycerin to Gouache

Glycerin is a transparent sweet syrup liquid. Since it is a humectant, it can accumulate moisture from the air in an area. Therefore, people can use it as a moistening agent. When an artist mixes Glycerin with Gouache, it traps moisture on the top layer of the color and extends its drying time.

If you want to discover more about the chemistry between Glycerin and Gouache, keep reading the article. Let’s start.

What is Glycerin?

Simply Glycerin or Glycerol is a clear, odorless, non-toxic syrup-like liquid. In 1779, a Swedish scientist named K. W. Scheele discovered Glycerin. Since it is an alcoholic sugar fermentation, it tastes sweet. It is water-soluble as it owns three-three hydroxyl groups and has extensive use in different industries.

Glycerin for painting
Glycerin for painting

Generally, manufacturers derive Glycerin from various animal and plant-based sources. However, animal and plant-based Glycerin are almost similar, with a few exceptions. Furthermore, people can extract Glycerin through chemical processes of saponification, hydrolysis, and transesterification of triglycerides.

Glycerin is immensely popular due to its hydrating effect. It is an outstanding humectant agent, which can accumulate water or moisture from the surrounding environment. Genuine Glycerin can take in water almost equivalent to its own weight over three days. This hydrating feature of Glycerin has made it extremely popular in the beauty industry.

What is Gouache?

Gouache is a thicker kind of watercolor. But Gouache paint differs from others in that artists can use it as watercolor and acrylic color. Since Gouache includes a high proportion of Arabic Gum, it can act as acrylic. In contrast, the more you add water to it, the more it becomes watery. There are different types of gouache such as traditional gouache vs jelly gouache.

Glycerin added gouache color painting
Painting with glycerin added gouache color

However, the excessive amount of binder restrains the pigments’ capacity to sit delicately on the paper as watercolors do. Therefore, premium-quality Gouache paints contain a greater amount of dry pigment to enhance the smoothness.

Some key features of Gouache:

  • Gouache is a vibrant watercolor that painters can use as watercolor and acrylic color
  • The heavy thickness of the paint makes it ideal for creating multiple layers or adding details.
  • It dries quickly.
  • Gouache is reactivable with water since it is water-soluble.
  • It offers a good coverage power
  • Gouache paints tend to crack if thickly applied.

Why do artists add Glycerin to Gouache?

One of the vital features of Gouache paint is that it dries faster. As the water evaporates, the color dries in ten to twenty minutes. However, drying time further shortens in warmer environments because water evaporates more quickly, which makes it difficult for the artists to sustain the liquidity of the paint. Even sometimes, the color dries on the color mixing palette before being applied to the paper. Therefore, some artists add Glycerin to Gouache paints for the below-mentioned reasons:

  • Extending the drying time:

Glycerin is a humectant agent. That means it traps moisture from the surroundings. More specifically, it collects moisture on the top layer of the products with which you have mixed Glycerin. Therefore, it prevents the dehydration process. Similarly, mixing Glycerin with Gouache paints will keep it moisturized and extend the drying time.

  • Reducing the cracking tendency:

Gouache paints often crack due to their inherent components. To solve this problem, artists add Glycerin to Gouache paints as a plastifier. Glycerin’s moisture prevents the paint’s cracking or peeling tendency in dried condition.

How to add Glycerin to Gouache paint?

Glycerin acts as a hydrator and plastifier when mixed with Gouache paints. But too much Glycerin can make your paint sticky that will take forever to dry. Therefore, one should use Glycerin in the proper amount that I mentioned below:

How to add Glycerin to Gouache paint
Adding glycerin to paint color
  • Shake the glycerin bottle to mix the water and Glycerin before use
  • Take gouache colors on the color mixing pallet as needed
  • Now use one drop of Glycerin with each color shade
  • Mix the Glycerin and color properly

Note: Avoid using too much Glycerin since it will longer the drying time and make the paint prone to dust.


One of the most challenging issues of using Gouache color is its faster drying tendency. Therefore, professionals often mix Glycerin to Gouache paint to retain the color’s flexibility. But many newbies don’t know the reason and process of adding Glycerin to Gouache paints. Therefore, I have thoroughly discussed the process and reasons behind using Glycerin in this article. I hope the readers will find the article helpful in fostering their skill.