The 3 Most Common Gouache Mistakes and How to Fix Them
Gouache is the dramatic, high-maintenance genius of the art world. It’s bold, it’s moody, and if you don’t treat it right, it has no problem letting you know that you’re doing something wrong.
Today, I’m tackling the three biggest gouache struggles; blending, layering, and consistency, and giving you quick, no-nonsense fixes so you can stop fighting with your paint and start making magic.
And here’s the secret- all these problems are caused by the same thing:
Too Much Water
Problem #1: Your Blending is a Streaky Disaster
In theory, buttery smooth transitions. In practice? Patchy chaos.
If your gouache blends look more like they were applied with a yard brush, here’s what’s going wrong:
Too much water in the mixture means that the pigment can spread out unevenly causing patchiness.
Letting the paint dry before you’re finished blending makes it so much harder to get great results
Not using enough paint means that the pigment is spread too thin, letting the white of the paper show through instead of that beautifully opaque coverage that we’re looking for.
The Solution:
👉 Stop adding so much water! Your poor gouache is drowning. Water is a tool we use to move the pigment around. You want just enough to let your paint slide across the page, and no more! It’s far easier to handle gouache that’s a little too dry than too wet.
👉 A clean barely damp brush is your secret weapon. I use this to gently fuss the colors together in short overlapping strokes. The little bit of moisture in the brush is just enough to allow the colors to blur together beautifully. Just be sure to rinse your brush clean and blot any excess water from the bristles often to avoid muddying the colors.
TIP: There’s two supplies that make a massive difference when it comes to blending; cold pressed cotton paper and a fluffy mop brush.
Cold pressed cotton has a little texture or tooth to the surface. This helps to grip the paint and stops it from sliding around too much, meaning when it comes to blending we don’t have to tiptoe around.
My favorite method of blending involves adding whatever colors I want in roughly the right location:
Looks pretty scary right?
Then we apply a thin sheen (not sopping wet) of clean water to the whole area, before tickling the colors together with a dry fluffy mop brush.
The tips of the bristles should barely touch the surface, and you can work in small circles over the area where you want the colors to blend together.
Blot any excess moisture and pigment from your mop brush often to keep those colors clear, and admire your beautiful blends…
Problem #2: When You Layer, You Lift the Paint Below
So you’ve done your background and you’re adding your details over the top. It’s going great until all of a sudden your background has reactivated and you’ve got this kind of black hole of moisture that won’t accept any more paint, your details have become a muddy mess- surely another dab of paint will fix it……
Just stop.
This is a classic gouache tantrum. It’s letting you know that there’s too much moisture and it needs a moment to dry… completely. Put the brush down.
The Solution:
Once it happens you’ve gotta let it dry completely. I know, I know, we’re impatient, but slapping wet paint onto damp layers is asking for trouble.
To avoid it happening in the first place we can:
👉 Use thicker paint. Every little bit of water in your mixture is trying to reactivate the paint that’s already on the page. Less water equals less chance of reactivating the layers.
👉 Stop fussing at the page. We want clean strokes that go over an area no more than twice. Light, gentle strokes will help keep the layers intact.
👉 And if gouache just won’t stop lifting? Switch to cold pressed cotton. The surface texture and extra absorbency that helps with blending makes layering much easier too!
My Favorite cold-pressed cotton sketchbooks are this watercolor one, by Hahnemuhle, or the Etchr Everyday Sketchbook.
Problem #3: Your Gouache Consistency is a Little Inconsistent
Sometimes it’s too thick, sometimes it’s a sad watery puddle, and sometimes it’s both at the same time. How does it even do that?
Gouache is a little bit sensitive when it comes to moisture, but this is an easy fix. Stop adding so much water. In my years of painting and troubleshooting gouache issues I’ve only ever seen one person use it without enough water. Every other consistency issue is always too much moisture.
The Solution:
👉 Use brushes that are designed for acrylics. These are not absorbent and will not hold lots of extra moisture in the bristles. Those expensive watercolor brushes you’re using are gouache’s idea of a nightmare. They hold way too much water.
👉 Learn how the gouache moves at different consistencies. Straight from the tube it’s often sticky and plasticky. Whereas a little moisture makes it glide so buttery smooth. This glide is what we want.
👉 Add water a little at a time. When you want to add water to your gouache, use a touch of a wet brush at a time and then blot your brush. And be sure to mix well- we want the pigment to be suspended evenly in that extra moisture
👉 Get into the habit of tapping excess water out of your brush. Added a little water to your mixture? Blot. Cleaned your brush? Blot. Don’t know what to do next? Probably blot. It’s really easy to carry extra water to your palette and your paper without realizing it until there’s water everywhere and you don’t know why.
TIP: And no surprise, cold press cotton helps with this too. Its extra absorbent nature makes it a little more forgiving than other surfaces, especially if you’re struggling to get your consistency quite right.
The Reading Tree, from The Talekeeper’s Emporium collection in Get Gouachey.
So next time your painting session becomes a battle of the wills between you and your gouache, give these a try. When it all comes together you’ll create absolute magic!
Want Help Putting This Into Practice?
If you’re tired of gouache’s drama and want some tutorials to help put your new skills to good use, then check out Get Gouachey; there’s hundreds of projects to paint to help you master this quirky medium with confidence.
Until next time,
Happy painting!