Quick answer: To make gouache from watercolors, increase opacity by mixing tube watercolor with an opaque white, either white gouache or Chinese (zinc) white for light colors, or a small amount of an inert filler such as precipitated chalk plus a few drops of gum arabic for mid and dark colors. Use less water than you would for washes, aiming for a creamy consistency. Naturally opaque pigments such as cadmiums, earths and cerulean blue give the best results; transparent pigments will only become semi-opaque.
Gouache is essentially watercolor with more body and opacity. That shared DNA means you can turn the watercolors you already own into a usable gouache substitute with a few additions. Learning how to make gouache from watercolors is handy when you need opaque highlights mid-painting, want to try gouache techniques before buying a set, or simply enjoy mixing your own paint.
This guide explains why the method works, three practical approaches, recipes and ratios, how to handle dark colors, and how to store your homemade paint.
Why Watercolor Can Become Gouache
Both paints use gum arabic as the binder. The differences come down to three things:
- Pigment load: Gouache generally contains more pigment relative to binder.
- Opacity: Many gouaches include an inert white filler, such as chalk or blanc fixe, that scatters light and hides what’s beneath.
- Consistency: Gouache is used creamy, not watery.
By adding opacity and reducing water, you move watercolor toward gouache. You won’t perfectly match a professional gouache, but you can get close enough for many purposes. If you’d like a benchmark for what well-made commercial gouache looks like, our guide to gouache paint sets explains what separates smooth, opaque formulas from chalky ones.
What You Need
- Tube watercolors (pans work but are slower to mix in quantity)
- White gouache or Chinese white watercolor
- Optional: precipitated chalk (calcium carbonate) or blanc fixe powder from an art supplier
- Optional: liquid gum arabic
- A palette knife and a smooth glass or ceramic mixing surface
- Small airtight containers or empty half pans for storage
- A dust mask if you handle dry powders
- Black marker and scrap watercolor paper for opacity tests
Method 1: Add White for Opaque Tints (Easiest)
This is the quickest way to make watercolor opaque and is ideal for highlights, skies and pastel colors.
- Squeeze a small amount of watercolor onto your palette.
- Add white gouache or Chinese white. Start with roughly one part white to two parts color.
- Mix with a palette knife or brush, adding water a drop at a time until creamy.
- Paint a test stroke over a black marker line on scrap paper. If the line still shows clearly, add a little more white.
Pros and cons
It’s simple and fast, but every color becomes lighter. White also cools and dulls some colors slightly. This method suits pastel and light passages, not deep darks.
Chinese white vs white gouache
Chinese white is zinc white made for watercolor. It is somewhat translucent, so it gives soft opacity. White gouache, often titanium-based, is more opaque and covers more strongly. For true gouache-like coverage, white gouache usually works better.
Method 2: Add an Inert Filler for Body Without as Much Lightening
Commercial gouache makers often use fillers to increase opacity. You can do the same with precipitated chalk or blanc fixe, which are white powders but far less tinting than white pigment.
- Wear a dust mask and work away from drafts when handling powder.
- Place a small amount of tube watercolor on a glass palette.
- Add a pinch of chalk, roughly one part chalk to three or four parts paint by volume.
- Add one or two drops of gum arabic to help bind the extra powder.
- Mull the mixture with a palette knife, pressing and folding until smooth and free of grit.
- Add water drop by drop to reach a creamy consistency.
- Test over a black line and adjust.
Why gum arabic matters
Fillers absorb binder. Without extra gum arabic, the paint can become chalky, dusty or prone to rubbing off when dry. A small amount restores adhesion. Too much makes the paint shiny and can cause cracking, so add it sparingly.
Method 3: Use Less Water and Opaque Pigments
Some watercolor pigments are naturally opaque. Used thickly, straight from the tube with very little water, they behave much like gouache. This is the simplest approach if your palette already includes opaque colors.
| Generally opaque watercolor pigments | Generally transparent watercolor pigments |
|---|---|
| Cadmium yellows, oranges and reds | Phthalo blue and green |
| Cerulean blue | Quinacridone reds and magentas |
| Yellow ochre and many earth colors | Hansa yellows (many are semi-transparent) |
| Chromium oxide green | Dioxazine violet |
| Titanium and zinc whites | Many staining modern pigments |
Opacity varies by brand, so check the label or test over a black line. Many manufacturers print an opacity symbol on tubes.
Recipe Table: Starting Ratios
| Goal | Watercolor | White gouache | Chalk | Gum arabic |
|---|---|---|---|---|
| Opaque pastel tint | 2 parts | 1 part | None | None |
| Opaque mid-tone | 3 parts | Small touch | 1 part | 1–2 drops |
| Semi-opaque dark | 4 parts | None | Small pinch | 1 drop |
| Opaque highlight | 1 part | 2 parts | None | None |
These are starting points. Brands vary in strength, so adjust by eye and always test on scrap.
The Challenge of Dark Colors
Darks are the hardest part of homemade gouache. Any white or filler lightens and dulls them. A few strategies help:
- Use as little filler as possible and rely on paint thickness.
- Choose naturally opaque darks, such as burnt umber, Payne’s gray formulas containing opaque pigment, or a mix with an opaque black.
- Layer twice. Two thin, creamy coats can cover better than one thick one.
- Accept semi-opacity and paint darks first, then add opaque lights on top, which is how many gouache painters work anyway.
Working From Pan Watercolors
Pans hold dried paint, so getting enough color for a creamy gouache mix takes a little patience.
- Mist the pans with water from a spray bottle and wait a minute or two so the surface softens.
- Use a damp, stiff synthetic brush to scrub up concentrated color and transfer it to a clean palette well. Repeat until you have a small puddle of thick paint.
- Let the puddle sit briefly so excess water evaporates, or blot the brush on a paper towel between loads.
- Add white gouache or chalk and gum arabic as described above, mixing with a palette knife.
Expect to make smaller batches than you would from tubes. For larger opaque areas, tube watercolor is far more efficient.
Troubleshooting Homemade Gouache
| Problem | Likely cause | Fix |
|---|---|---|
| Paint looks streaky | Too much water or uneven mixing | Add more paint, mix longer, apply with a fully loaded brush |
| Dried paint rubs off as dust | Too much chalk, not enough binder | Add a drop or two of gum arabic to the next batch |
| Surface looks shiny or cracks | Too much gum arabic or paint applied too thick | Use less gum arabic and thinner layers |
| Colors look chalky and pale | Too much white | Reduce white; switch to chalk for body |
| Lower layers lift when painting over | Normal rewetting of gum-based paint | Use a light touch, fewer strokes and creamier paint |
| Gritty texture | Undispersed powder | Mull longer with a palette knife on glass |
How to Use Your Homemade Gouache
- Mix enough for each area before you start; matching homemade mixes later is tricky.
- Keep it creamy. Too thin and it turns back into watercolor; too thick and it can crack.
- Paint flat shapes with a fully loaded brush in single, confident strokes.
- Layer gently. Like gouache, it rewets, so avoid scrubbing lower layers.
- Test the dry color. Gouache-style paint often shifts in value as it dries.
How to Use Gouache Paints Over Watercolor Washes
One of the best uses for homemade gouache is finishing a watercolor painting. Lay in your transparent washes, let them dry completely, then use opaque mixes for:
- Highlights on water, eyes, metal or glass
- Fine light details such as grasses, branches or hair
- Correcting areas where you lost the white of the paper
- Adding birds, snowflakes or stars against a dark sky
Building a Small Homemade Gouache Palette
Rather than converting every watercolor you own, make a compact set of five or six opaque colors you’ll actually use. A practical starting group is a warm yellow, a warm red, a cool blue, an earth color such as yellow ochre or burnt sienna, a dark, and a generous amount of white. Mix each with your chosen method, fill a half pan or small jar, and label it. With white on hand, these few colors can produce a wide range of opaque tints for highlights and details, and the set fits easily in a sketching kit.
Storing Homemade Gouache
- Short term: Keep mixes on a covered ceramic palette or in a wet palette for a day or two.
- Long term: Fill empty half pans or small airtight jars and let them dry. They rewet like watercolor pans.
- Label everything with the colors and ratio so you can repeat favorites.
- Watch for mold in wet storage, especially if you added honey or glycerin. Discard anything with an off smell.
Homemade vs Store-Bought Gouache
| Factor | Homemade from watercolor | Commercial gouache |
|---|---|---|
| Cost | Low if you own watercolors | Moderate to high |
| Opacity | Good for lights, weaker for darks | Consistent across colors |
| Consistency | Varies by batch | Uniform |
| Convenience | Requires mixing | Ready to use |
| Best for | Highlights, experiments, small studies | Finished illustrations and larger works |
If you find yourself mixing homemade gouache often, a basic set of real gouache may save time. The best gouache paint sets for artists and crafters are compared by opacity and value in our buyer’s guide.
Common Mistakes
- Adding too much white and turning every color pastel.
- Skipping gum arabic when using chalk, leading to dusty paint.
- Adding too much gum arabic, causing shine and cracks.
- Using transparent pigments and expecting full opacity.
- Painting too thin. Watery mixes lose the gouache effect.
- Mixing large batches before testing. Make a pea-sized test first, check it dry, then scale up.
- Breathing in dry powders. Always wear a mask when handling chalk or pigment powder.
A Practice Exercise
To learn the method, make a small opacity chart:
- Draw five thick black marker lines across a sheet of watercolor paper.
- Choose one watercolor and make five mixes: plain, with a little white, with more white, with chalk and gum arabic, and with both.
- Paint a stripe of each mix across the black lines.
- Once dry, compare how well each hides the lines and how much each mix lightened the color.
Repeat with a transparent color and an opaque color. You’ll quickly see which approach works best with your paints.
FAQs
Can you turn watercolor into gouache?
Yes, approximately. Adding white gouache, Chinese white or an inert filler like chalk, and using less water, makes watercolor opaque enough to work like gouache.
What white is best for making gouache from watercolor?
White gouache, typically titanium-based, gives the strongest opacity. Chinese white (zinc) is softer and more translucent.
Is homemade gouache as good as real gouache?
For highlights and light colors it can be close. Darks are usually less opaque, and consistency varies between batches.
Can I add acrylic white to watercolor to make gouache?
You can, but the mix will dry water-resistant and won’t rewet like gouache. It behaves more like acrylic gouache.
How to make gouache paint from watercolors without white?
Use naturally opaque pigments thickly with very little water, or add a small amount of chalk and gum arabic, which lightens less than white pigment.
Does homemade gouache reactivate with water?
Yes, if made with watercolor, gouache or chalk and gum arabic. It rewets just like regular gouache.
Final Thoughts
Making gouache from watercolors is a practical skill: a little white or filler, less water and smart pigment choices give you opaque paint whenever you need it. Use it for highlights, corrections and experiments, and when you want reliable, consistent opacity across every color, look at our top-rated gouache paints for vibrant artwork to find a set that fits your work.
