How to Thin Acrylic Paint: A Useful Guide

A lot of people ask how to thin acrylic paint. It’s a question that’s not always easy to answer, so we decided to write an article about it. We cover things like the best type of mediums and the correct ratios for the different types of paints in this post – so you can get started with your own painting project without any problems!

What Is Acrylic Paint?

Acrylic paint is a type of water-based, quick-drying, and permanent paint that uses pigments rather than dyes. It’s the most popular form of painting amongst beginners because it requires no special equipment or training to use – just an empty cup for mixing! Acrylics are very versatile too.

Although there are hundreds of different brands on the market today, they all fall into three main categories according to their consistency (which varies depending on which brand you choose):

  • Thick acrylic paints
  • Semi-thick acrylic paints
  • Solvent-thinned/medium visity

When choosing how much paint to add, keep in mind that thicker paint is more opaque and creamy while thinner paints are translucent.

What Does Acrylic Paint Contain?

Acrylic paint is made up of four main components:

  • Pigment
  • Binder
  • Solvent
  • Water

Pigment is the colorant in a medium. It determines what we call the opacity or transparency of colors when they dry – how much light gets through to the other side (the more opaque it is, the less you’ll see). Pigments can be organic or man-made and come in many different varieties such as iron oxide reds and yellows; zinc white; phthalocyanine blues; cadmium oranges; etc.

Binder is the chemical that holds pigment particles together to form a uniform film. It’s what gives paint its thick, creamy consistency – without it, paints would be watery liquids! The most common binders are acrylic resin emulsion, vinyl acetate-ethylene terpolymer dispersion, cellulose ethers such as methylcellulose or hydroxymethylcellulose sodium salt solution etc.

Solvent helps pigments disperse in fluid mediums evenly by acting as an agent for dissolving both binder and pigment. When mixed with paint, solvent molecules act as tiny little magnets for all three components (pigment, binder and water) which is what helps paints flow better. The most common solvents are water; ethanol; methanol; acetone etc.;

Water is the fourth component of acrylics. It’s not actually included in the chemical structure but it does play a part by attracting pigment particles to one another so they form larger clusters called “floccules”. More flocculation means more opacity – perfect for covering up mistakes or creating interesting color effects! Water can also help control how quickly paints dry on surfaces depending on their thickness since thinner pigments will take longer to reach full strength than thicker ones.

Check out our tutorial on How to Dispose of Acrylic Paint and Be a Responsible Artist!

Are You Supposed to Thin Acrylic Paint?

Thinning acrylic paint is actually an important part of the process because it makes paints flow better. It isn’t always necessary but it will help you achieve certain effects or work in specific ways so, if you want to do that, then go for it!

Thinner acrylics also give off a sheen when dried since there’s more solvent left behind than pigment; while thicker ones tend to become opaque because of all the extra binder used during mixing. This means thin paints retain their translucency better than thick ones – making them ideal for glazing techniques like washes, etc.

Does Thinning Paint Change the Color?

Thinning doesn’t actually change the pigment or its chemical composition – it just reduces the viscosity of paints so that they flow better and dry faster.

Thinner paint will absorb into surfaces more readily without leaving much behind, while thicker ones may take longer to seep in but tend to leave a “film” on top which can mask details if over-applied.

Of course, adding too much solvent at once will thin acrylics down completely until they become watery liquids (which then probably won’t work for most projects!).

What to Use to Thin Acrylic Paint?

There are a lot of possible solvent options when it comes to thinning acrylics – from water and mediums to acetone. Water is the most common choice but you can also use other types if they’re more readily available since different solvents will give off specific results depending on their properties.

Mixing in too much solvent at once may cause paints to become runny so experiment with small batches until you achieve just the right consistency for your projects!

How to Thin Acrylic Paints with Water

If you’re using water to thin acrylic paint, then just add a few drops at first and mix it in thoroughly. Keep adding small amounts until your paints are the consistency that you want! If they become runny after mixing then take out some of the thinner with an eyedropper or pipette because too much water will make them ineffective for most projects.

The most common ratio to use is 30% of water to your paint. Use distilled water if you feel like your tap water may be too impure or contain chemicals that could affect your results!

How to Thin Acrylic Paints with Acrylic Mediums

Acrylic mediums are another great way to thin out acrylic paint so you can achieve specific effects. They’re basically just different types of solvents with special properties that make them easier for artists to work with by improving color flow, extending drying time or promoting adhesion between layers, etc.

Mediums sometimes come premixed in small bottles but they’re often diluted before use because the ratio of solvent-pigment is pretty high already – which makes it easy for paints to become too runny if used as instructed!

Mediums are great because they allow you to add more solvent while still maintaining the same color purity and opacity – which is why it’s also recommended that beginners use them instead of water so they don’t accidentally thin their acrylic paints too much. You need to add up to 20% of acrylic medium to your paint.

How to Thin Acrylic Paint with Acrylic Binder

The third way to thin acrylic paint is by using a type of solvent called “acrylic binder”. This may be something that you’re familiar with already since it’s actually part of the mix before adding pigment – but if not, then now might be a good time to learn more about this useful solvent!

Acrylic binders are usually clear liquids that can also double as mediums for extending drying times and improving adhesion between layers.

They’ll turn your paints into gels instead of fluids so they won’t become too runny when used properly – making them perfect for most projects involving fine details or delicate effects! Binders were originally developed as an alternative to toxic solvents like turpentine because people have respiratory problems from inhaling them.

Remember not to add more than 50% of acrylic binder to your paint.

How to Thin Acrylic Paint with Acetone

Acetone is another useful solvent when working with acrylics because it makes colors flow better, dries faster and enhances adhesion between layers, etc. It can even be used alone without mixing in any other medium or water!

However, there’s one thing you need to know about using this kind of thinner: acetone evaporates very quickly – sometimes within minutes depending on environmental conditions like temperature, etc. This means that you’ll need to thin your acrylic paints with it before adding them to an art project or painting surface.

How to Thin Acrylic Paint for Airbrush

Acrylic paints are usually sold as thick liquids perfect for painting techniques like stippling or dry-brushing, but they can be thinned out with water to make them easier to use with airbrushes too. If you’re looking for a method to thin acrylic paint for airbrushing, there are a few techniques and products which can be used.

When using water as a thinner it is best to mix between 40-50% of the total amount of paint being used with distilled or boiled water. The resulting mixture will have an easily sprayed milky consistency however some crafters prefer to use glazing mediums such as liquitex flow aid or gamsol.

This is especially useful if you want a more subtle finish on your art because acrylics don’t always mix well when fed through an airbrush – which means that some colors may clog up the nozzle of your device and ruin it!

Other things that can be added during this process include matte medium, essential oils, alcohol ink thinner, even high-quality vodka can be added to a thinned acrylic paint mixture. The mixing possibilities are virtually endless!

Keep in mind that using thinner will decrease color quality slightly so it’s best not to do this unless absolutely necessary. It’s recommended that beginners only adjust paint consistency with water since it’s much safer and easier to master compared to other solvents.

Homemade Acrylic Airbrush Thinner

You can also make your own thinner to use with an airbrush instead of purchasing it at the store. This is great if you have sensitive skin, are looking for a healthier option, or just want to save money!


  • Distilled water – 3 parts
  • Isopropyl spirit – 1 part
  • Glycerine – 15 drops

Mix the ingredients together in a spray bottle then apply as needed. It will be rather thin so it’s best used on acrylic colors that aren’t too thick already, but this mixture works wonders when trying to clean out clogged nozzles after several uses.

Using household items around your house can be both a fun and frugal way to get more mileage from your supplies without having to spend another dime on what might turn into unnecessary purchases down the line. Remember to always make a note of what you use and how much so that you can replicate the results later on!

How to Thin Acrylic Paint for Pouring

Pouring is a unique method of art that involves allowing the paint to flow over the surface of a canvas, plate or other flat objects in order to create interesting textures and designs.

There are two ways to thin acrylic paint for pouring. The first method involves mixing the paint with a clear medium, such as gel or varnish. You can also add retarder or painting medium into your mixture of color and water before you start applying it to the surface.

The second option includes adding some distilled water to your colors. The resulting texture should have an easily poured consistency without sacrificing too much color quality.

Like most things related to using this technique, there are no hard rules when thinning down acrylic paint so feel free to experiment with different mixtures until you find what works best for you. Remember that if your mixture is too watery or runny it will take a very long time to dry and may not hold together well!

Thinning Acrylics with Medium VS Water

Before deciding which method to choose when thinning paints, keep in mind whether pigmentation is an issue or not. If so, colorless gels will be a better choice than using water because they allow consistency without altering colors at all.

Adding water allows you to make shades and tints, which means working with color mixing this way will help create lighter tones.

You can also check out our article on How to Thicken Acrylic Paint.

How to Soften Hardened Acrylic Paint

If you accidentally leave acrylic paint out for a long period of time and it starts to dry, there are several ways to soften the mixture. The first involves adding water as usual but this method can be problematic if your colors have been mixed with mediums or other solvents – which will only end up diluting everything further!

The best solution is to use a different solvent that won’t affect dried paints at all such as mineral spirits (paint thinner) or acetone. They work wonderfully when trying to salvage hardened art materials from an airtight container since nothing else will dissolve them so easily.

Isopropyl rubbing alcohol works well for thinning out thick paints that have become dry over time, which makes this solvent perfect when working on large canvases or other projects where consistency needs to be adjusted mid-brushstroke without wasting too much color.


Always remember that thinning paints is a way to experiment with colors and learn more about the properties of acrylics before investing in new supplies.

Different types of solvents may offer specific benefits like increasing transparency; improving flow; extending drying time, etc.; depending on their own properties (which means knowing what mediums do is essential for getting the right results).

Keep this information stored away for future reference so that you can use it when needed without having to look up tutorials or different methods each time!

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