3 Gouache Mistakes That Could Be Ruining Your Paintings

Gouache is bold. It’s vibrant. It dries with a dreamy matte finish.

But if your paintings look dull, patchy, or just not right, you’re probably making one of these common mistakes.

And the worst part? You might not even know you’re doing it.

In this post, we’re breaking down the 3 biggest gouache mistakes beginners make.

More importantly? How to fix them—fast. So you can paint with more control, more confidence, and way better results.

Let’s get into it 👇

Mistake #1: You're Using Too Much Water

Gouache isn’t watercolour. But lots of beginners treat it like it is.

Many beginners load up their brush with water, expecting smooth blends. But in gouache? Too much water is a recipe for disaster.

What happens:

👉 Colors dry pale and streaky

👉 Paint loses its bold, opaque finish

👉 Layers turn muddy and uneven

💡 What to do instead:

Gouache should feel creamy, not runny.

Add just enough water to help it glide—but keep it thick enough to hold its colour. Think smooth frosting, not soup. A little water goes a long way.

Mistake #2: You're Rushing Your Layers

One of the trickiest things about gouache? It reactivates with water.

That means, your colours can bleed together, mix up, and turn into a muddy mess if you don’t let one layer dry fully before painting over it.

What happens:

👉 Edges blur

👉 Vibrancy fades

👉 Your painting loses structure

💡 What to do instead:

Patience is power.

Let each layer dry completely before painting over it. You’ll get cleaner lines, better contrast, and depth that pops.

Mistake #3: Only Using Flat Brushes

Flat brushes are great for laying down colour quickly—but they’re not made for everything.

What happens:

👉 Fine lines look chunky

👉 You struggle with details

👉 Edges feel clumsy instead of clean

💡 What to do instead:

Swap your brush to match the job.

Use round brushes or detail/liner brushes for sharper edges, delicate strokes, and controlled blending. The right brush makes a huge difference.

Bonus Tip: How to Fix Gouache Mistakes (Even When the Paint’s Dry)

Made a wrong stroke? Smudged a layer? Don’t stress.

Gouache is reactivatable—which means you’ve got more chances to fix things than you think.

✏️ Here’s how to clean it up:

If it’s still wet: Dab the mistake with a tissue or lift with a damp brush

If it’s dry: Use a clean, damp brush to gently scrub the area, then blot it with a paper towel

Need a full reset? Try a tiny bit of water with a Magic Eraser sponge—it works like a charm

This trick alone can save your favorite pieces.

🎥 Prefer watching instead of reading?

This blog post is based on our YouTube video, watch it here!

Don’t forget to like, share, comment, and subscribe for more.

Final Thoughts

Gouache doesn’t have to feel tricky or unpredictable.

Once you learn the right techniques—and stop following the wrong advice—you’ll get richer colours, smoother blends, and way more control over your work.

Mastering gouache is less about talent, more about knowing what not to do.

✅ Keep it creamy

✅ Let it dry

✅ Use the right brush

✅ And don’t fear mistakes. You can fix them!