How To Use Gouache With Watercolour

I love the unpredictability of watercolour and gouache, and in this tutorial I will introduce you to the materials I use while painting and the effect they have on the paints I use.

Why Use Paint Effects?

Painting is fun. Part of that fun is experimenting, and part of that experimentation is not knowing what is going to happen with a painting as you work on it. I find all of this very exciting.

Texture adds a great deal of interest to a painting, and watching someone walk up close to one of my pieces because they want to see what I have done more clearly is thrilling.

What You Will Need

Your imagination. Anything goes—you just need your usual paper and paint and patience to see if your ideas work.

Here are just some of the things I've been known to use in my paintings:

silicone
alcohol
salt
bleach
thread
clingfilm
gesso

An example of some of the items I use in my paintings

Water-Based Effects

Like every artist, I use plain water with my watercolour and gouache, but you don't have to do that all the time. I like to add a few things to it, resulting in different appearances. Below is a mix of watercolour and gouache with just plain tap water.

All the examples below are of a water mix put down on clean paper and then adding the paint in after.

1. Water Plus Salt

If I sprinkle a good helping of salt in my water, swirling it until it has dissolved, the paint spreads more and becomes granular.

Water plus salt

2. Water Plus Bleach

I love this effect. The colours are so soft, and they feather at the edges. Experiment with how much bleach you mix into your water—it's up to you, of course.

Water plus bleach

3. Water Plus Alcohol

I use either vodka (I'm a non-drinker, so I don't have any qualms about using it to paint with) or rubbing alcohol (bought online) for this. The alcohol puts a stop to the spreading of my paint.

Water plus alcohol

Clingfilm

Depending on where you are from, you may call this stuff something different—cellophane, cling wrap, or saran wrap are all different names for what I know as clingfilm. But it all does the same thing with watercolour and gouache.

Lay down your paint first, and while it is wet, place a strip of clingfilm on top. I move it around to get the patterns and shapes I want, and to get the direction I want them to be moving in.

Clingfilm

When the paint is dry, lift the clingfilm and you will be left with this...

Occasionally, I leave the dried paint and clingfilm and feed a new, more watery colour down inside while moving my paper at different angles, forcing the paint to spread about as it desires. I then wait until this is dry before lifting the clingfilm.

Gesso

Gesso is wonderful. It can be watered down to any consistency you prefer. I like painting it onto my paper and leaving the brush strokes in it. When it's dry, it is easy to paint over and scrape into (using a knife, nail, or pin), and it dries quickly.

You can also build it up into shapes you want (below), and if you make a huge mistake with something you are working on, you can use gesso to paint over it and start again.

Salt

A lot of watercolour artists swear by this, but I have to admit I find it a bit hit or miss (it just means I get to do more experimenting). The effects can be spectacular, but I find that although I do get a 2D texture, it isn't enough for me. I thought I should include it, though, because you may have more luck. I may have to look at the type of paper I use—I prefer to use rough, but smooth may work better. However, I have found that the type of salt does make a difference. I sprinkle the salt onto wet watercolour, and it does its magic as it dries.

This is what dried paint looks like without salt...

1. Table Salt

This tends to be the least successful as I find the grains are too fine.

Wait until the paint is dry before brushing off the salt. Some is likely to remain stuck to your paper, though.

You will end up with a slightly granulated effect and an uneven spread of colour, but that's what I tend to be looking for when I use salt.

2. Flaked Salt

This works better than table salt, and is easier to remove when it dries.

3. Rock Salt

My favourite. It soaks up the colour, leaving little star effects in the dried paint, and it's easily removed.

Just be patient when letting it dry as shaking it off your painting too early could leave you with wet paint trails where the salt has moved.

Bleach

I use this as pure bleach or watered down. I sprinkle it or paint it into my work. I use it on wet paint or dry. Something always happens, and the higher the concentration of the bleach, the more colour you lose. It's smelly but exciting stuff. Just be careful not to splash it on your clothes.

Below is bleach dropped onto dry paint. I have used pure bleach here, without watering it down.

Below is bleach dropped onto wet paint—there is more of a spread into the colour.

Blowing

It's not all about what you can add to your paint. Sometimes, just blowing and manipulating the directions you blow your paint in makes all the difference. You can also change the angle of your board, tilting it as you work to move the paint around your paper.

Crackle Glaze

I rather like this one. It dries clear, so it can be painted on top of what you have already done and can also be painted over.

Or you can rub into it, leaving a different colour in the cracks (below), and wiping off the excess on top, which allows the colour underneath to shine through.

Crackle glaze with paint rubbed into the cracks

PVA Glue

You can use this in a couple of ways. There's the obvious use as, well, glue, sticking papers and whatever else you wish to your work. I tend to thin it a bit with water when I do this as I use tissue or handmade paper that I can manipulate into the shapes that I want, like trees. It is then easy to paint on top of.

And then there is the option of mixing the glue directly into the paint. It gives it a soft sheen when it's dry...

... but it is not easy to paint on top of. I like the effect, though.

You can also mix sand into the glue for added texture—I've circled the effect below. In this example, I then did a thin coat of gesso on top, which allowed me to add paint without any problems. You could add sand to the gesso too.

Thread

You can either just drop the thread directly onto your paper or lay down a layer of paint first. The thread can be dipped in paint before placing it on paper or dabbed with paint after putting it on your paper. Or both.

Wait until the paint is dry and then lift the thread off. You can also use straw or hair for this.

Splashing

There are so many ways you can do this. Use a small brush, a large one, or a toothbrush. Splash onto dry paint, splash onto wet paint, or onto just water (or water with bleach, salt, or alcohol in it). Bang on the side of your brush's handle, or flick the loaded brush bristles themselves. Hold your brush high or very low, near to the paper. Whatever you do, the result always looks good.

Silicone

I've only just started to experiment with this, so who knows what I'll discover over the next while. Just make sure you wash your brush thoroughly with soap and water after use.

Here, the image above is split into two. I put down a layer of silicone, and on the left, I painted into it while it was still wet. The right was painted when the silicone dried.

Granulation Medium

I use granulation medium straight from the bottle instead of water. I mix it into my watercolour (it doesn't work with gouache) as I paint and angle my board, moving the paint around my paper. It breaks the pigment into tiny granules, giving added texture. It's wonderful layered on top of contrasting colours.

Conclusion

As I write this, I am coming up with all sorts of ideas I haven't yet tried or noting down ideas for future experimentation. What if I watered down silicone and used that as a water mix? Or what if I try mixing colour directly into the silicone? I need to try painting with pure alcohol and not mixing it with any water.

Your ideas may not always work, but the ones that do will be a wonderful surprise and make experimenting more than worthwhile. You are only limited by your own imagination.