How to Thin Acrylic Paint

thinning acrylic paints

Thinning acrylic paints may become a real headache for beginners and experienced artists. We need to thin paint to get better results in painting and the right method and thinning mixing ratio will com with experience, but I recommend you start learning and trying right now with my full guide.

How to thin acrylic paint? There are at least 6 ways for thinning acrylic paints: by adding water, a thinner, an acrylic binder, a pouring medium, acetone, or rubbing alcohol. The easiest but contradictory method is adding distilled water. The most effective way is to use specially made thinners. There are also some ingredients that should be never used as thinner such as spirits.

In this article, I will share with you the whole process of thinning acrylic paints depending on the medium, technique, and preferences. As manufacturers recommend using special thinners, I will also provide you 14 best acrylic paint thinners and some extra tips to make your painting process more enjoyable.


Table of content for How to thin acrylic paint:
  1. What is thinning acrylic paints?
  2. Are you supposed to thin acrylic paint?
  3. What to use to thin acrylic paint?
  4. How to thin acrylic paint
  5. 14 Best paint thinners for acrylic paint
  6. 3 Extra tips for thinning
  7. Related questions

What does thinning acrylic paints mean?

Thinning acrylic paints – is a process of adding to acrylic paints water or any other medium which will slowly dissolve paint making it thinner as a result.

The thinning acrylic paint also creates lighter consistency and viscosity.


Are you supposed to thin acrylic paint?

We are supposed to thin acrylic paint when the viscosity seems too thick for us. Thinning acrylic paints helps us get different consistency, colors, and effects (thinned acrylic paint may look like watercolor).

The thinning acrylic paints process can seem easy, but without proper experience and guidance, it could be difficult to achieve the desirable effects.

For a better understanding of why we need to thin acrylic paint and what do you thin acrylic paint with, you should know exactly what is acrylic paint and what are its main characteristics.

Acrylic paint composition:
  • pigments give color to paints

  • binder has 3 main functions: assuring waterproofness, gloss, and fast and even drying

  • other agents provide durability.
Acrylic paint composition

One of the main characteristics of acrylic paint is its water-soluble property. Acrylic polymer emulsion is a binding and pigmenting agent that makes acrylic paint water-soluble and sensitive to thinning acrylic paints.

Remember this term – acrylic polymer emulsion – if you see acrylic polymer emulsion in the thinning medium composition, it means pigments will be bond and permanently stay on your canvas and your paint will not peel. Water doesn’t contain any acrylic polymer emulsion.


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What to use to thin acrylic paint?

We agree now that before painting we should thin our paint. What to use to thin acrylic paint? There are 2 most popular ways to thin acrylic paint: water and range of mediums.

What to use to thin acrylic paint

In fact, many people, especially artists who worked with oil before, wonder if you can thin acrylic paint with alcohol, spirits, or acetone. Despite the popularity of thinning acrylic paints with water, some painters say that you should never use water to thin your paint. I will help you to see all the precautions to each method and help to choose the best method how to make acrylic paint thinner.

  1. Thinning with water
  2. Thinning with mediums
  3. Thinning with spirits

Thinning acrylic paints with water

Can you dilute acrylic paint with water? Yes, you can thin acrylic paint with water. Water is the most common and cheapest ingredient to thin acrylic paint. Water is the easiest way to thin acrylic paint because water affects the composition directly, more specifically – the binder, and slowly dissolves it. But this method is not highly recommended for beginners because even a slight over-pouring of water can potentially ruin the painting.

The right ratio for thinning with water depends on what effects you need and the surface you paint on.

The best way to thin acrylic paint with water is to mix 30-50% of the water with the paint (1:2 ratio).

  • 30% of water or less to acrylic paint thins it lightly and allows you to coat a surface. Add 30% water when your work with pre-primed surfaces.
  • 50% of water or more creates a watery paint effect called a wash.
Personally, I never use more than 30% of water based on my technique and preferences in abstract painting.

Precautions:

  • Use only distilled water.
  • Always put a small amount of paint on your palette to make sure you do not waste paint by letting it dry.
  • If you experimenting with thinning for the very first time, try to thin your paint with a different amount of water on different palettes. Make notes and remember which ratio was the best for you.
  • Use a separate brush to thin acrylic paint with water. Wipe and wash it immediately after thinning.
  • Do not add more than 50% of water to avoid peeling. Water breaks binder, the molecules patterns which “glue” the pigment particularly. Water itself doesn’t hold coloring pigment together. Thinning acrylic paint with too much water can result in flaking off and eventually will ruin your painting over time.
  • The amount of water does not matter, as any excess is absorbed, and the pigment will remain on the surface when you paint onto an unprimed surface.
Gentle reminder: use water to thin acrylic paint and then to paint only on primed and well prepared surfaces. Unprepared paper, canvas or wood will soak the water and harm paint adhesion, quality or longevity of the painting. 

Liquitex manufacturer in their official FAQ do not recommend water for thinning acrylic paint.


Thinning with acrylic mediums

The thinning medium method is the best way to thin acrylic paint for beginners because you don’t have to worry about the ideal ratio and eventual peeling of the paint. This approach is the most effective way to preserve your paintings over time.

There are several mediums which you can use to thin acrylic paint. Mediums still bond the pigment with the surface, increase UV resistance of the pain and help to achieve different effects, e.i.: watercolor look, glazing; matte, satin, or gloss finish effects; extended dry time; color extension; increased flexibility; additional cracks; shaped surface, etc.

The thinning mediums were designed to thin acrylic paint. Their only disadvantage is the price – they can be quite expensive. But if it will make your painting last longer or cost more, it is worth it, right?

What mediums I can use to thin acrylic paint:
  • Airbrush medium is almost as thin as water and provides smooth application
  • Flow improvers are expensive and good for professional artists. They create a stain effect and as the name says improve paint flow.
  • Acrylic Binder
  • Pouring medium

Here, in one of the sections below, I sum up best acrylic thinners for you with prices and notes.

Precautions

  • Use only good quality thinning mediums
  • Use your thinner according to the manufacturer instructions

To thin acrylic paint with a binder

As we remember, a binder is a part of the acrylic paint composition. The binder assures waterproofness, gloss, and fast and even drying of the paint.

Using a binder as a thinning medium is a good decision because you will not have to think about the best ratio for mixing or worry about unbound paint. On the contrary, a binder can add more shine and gloss and will prevent paint from soaking into the surface.

The only precaution you should keep in mind is: do not add more than 50% of acrylic binder to thin paint.

Acrylic binders you can use: Chroma Fusion I.A. Series Pro-Grade Binder Medium and PEBEO Studio Acrylics Auxiliaries, Bindex

Here, in one of the sections below, I sum up best acrylic thinners for you with prices and notes.


Thinning acrylic paint with pouring medium

The pouring medium was specifically designed for acrylic pouring, but you can use it also for acrylic painting. The pouring medium improves the flow and does not affect pigments or color intensity.

To thin acrylic paint with pouring medium you add 10% to 20% medium to your paint. Be aware that pouring medium make paint dry slower.

Pouring mediums you can use: Liquitex Professional Pouring Effects Medium, Golden Artist Colors Color Pouring Medium, DECOART Pouring Medium.

Here, in one of the sections below, I sum up best acrylic thinners for you with prices and notes.


Thinning acrylic paint with spirits and paint thinners

Some artists prefer to use various chemical thinners for thinning acrylic paint. You can also try it with all precautions and strictly following manufacturers’ guidelines.

Spirits as thinning medium act like solvent. Do not use too many chemical paint thinners in order not to damage the colors.

This is NOT a recommended thinning method for beginners. The best way to thin paint is to use mediums, not spirits.

Can you thin acrylic paint with alcohol?

You can thin water-based acrylic paint with isopropyl (rubbing alcohol). The recommended amount of alcohol you can use to dilute paint is up to 20%.

The using of alcohol will accelerate drying and can result in uneven application.

Thinning acrylic paint with alcohol is NOT a recommended thinning method.

Can you thin acrylic paint with mineral spirits?

You can NOT thin water-based acrylic paint with mineral spirits because they are petroleum-based and will significantly decrease paint adhesion. Thinning acrylic paint with mineral spirits is NOT a recommended thinning method for water-based paints.

Can you thin acrylic paint with acetone?

You can thin acrylic paint with acetone. The ratio is a 4:1 ratio of paint to acetone.

Thinning acrylic paint with acetone is NOT a recommended thinning method for a beginner.

Can you use white spirit to thin acrylic paint?

You can NOT thin water-based acrylic paint with white spirit. These two ingredients will not mix Thinning acrylic paint with white spirit is NOT a recommended thinning method for beginners.


How to thin acrylic paint

We went through why we thin acrylic paint, what you can potentially use to thin paint and now we move on to how to thin out acrylic paint. I suggest you the general guidelines and 3 specific cases of thinning:

I also have for your the quick and useful infographic, feel free to use it and print. Below you will find detailed instructions for every method and list of precautions, as well as 14 best acrylic paint thinners.

How to thin acrylic paint

How to thin acrylic paint

  1. Put a small amount of paint on your palette.​ Always work with small amounts of paint because acrylics dry in 20 – 30 minutes.
  2. Add water or thinning medium.
Thinning acrylic paint with waterThinning acrylic paint with mediums
Be very careful with water!
Add 30-50% of water to your paint.
Mix thoroughly with a spare brush.
There is no rule about the ratio for thinning mediums.
* If you use pouring medium, add 10-20% of it to paint
* If you use an acrylic binder, add up to 50%
Mix with a palette knife.

3. Check the consistency. Take your palette knife or squeezed brush and apply paint to check if the consistency is right for you.

4. Paint. If you’ve achieved the consistensy you were looking for, start painting.

Reminder: Make sure you start painting on a well prepared surface, e.i. primed canvas, sanded, sealed and primed wood etc. 

If you are not sure that you surface is ready and you prefer to avoid peeling and cracking, check my full guides about priming wood, gesso and isolation coat to make sure you're following the right process.

How to thin acrylic paint for spraying

Thinning acrylic paint for spraying is a key step to successful spraying. If you want to control the results, even application and paint consistency, you need to thin acrylic paint for spraying. You also should consider thinning when the weather makes your paint thicker (temperature, humidity, and air pressure).

The spraying techniques use different paints: oil-based, acrylic and latex are most popular. In fact, the thinning process will also depend on what paint you choose to use with a spray gun. I will not cover oil-based paints here because my experience and blog are focused on acrylic.

How to thin acrylic paint for spray gun

The best way to thin acrylic paint for a spray gun depends on the type of sprayer. The most common types are HVLP (High Volume, Low Pressure) paint gun, and an airless spray gun.

Please, follow some easy recommendations on how to thin acrylic paint for spray gun below.

HVLP (high Volume, low Pressure) paint gun

HVLP (High Volume, Low Pressure) paint gun is good for oil-based and latex paints. You thin acrylic paint for HVLP gun with 10-30% water depending on your preferences.

If you use acrylic latex paint in a non-friendly environment, you can mix your paint with a paint conditioner without thinning. This will make your paints less sensitive to environmental factors and thinner. In any other case, do not use paint conditioner, because technically it is not a thinner.

Do I need to thin paint for airless sprayer?

If you use latex paint with an airless spray gun, you don’t really need to thin paint. It is still recommended, especially when you use small spraying systems. If you need to thin acrylic paint for an airless spray gun, add 20% water to the paint.


How to thin acrylic latex paint for spraying

Thinning acrylic latex paint for spraying is highly recommended, as latex paint itself is thick.

  1. Blend the latex paint thoroughly.
  2. Put the amount of paint you need to a cup or container. Do not add too much paint because latex paint becomes even thicker drying.
  3. Add water by small drips. You need even consistency and viscosity. Basically, you will need 10% to 30% of water.
  4. Mix and stir thoroughly, checking if the consistency is right.
  5. Fill the spray gun with a small amount of paint to test – the paint should flow smoothly through the cup. Test thinned acrylic latex paint on cardboard or some surface similar to the one you will use. Do not use plywood.
  6. If you need, repeat steps 3 to 5. If you’ve achieved desirable consistency, fill the spray gun and start spraying.
If the paint is too thin, you can not use it! Too thin - it means it flows too fast through cup (funnel).

Slowly add more paint and check the consistency and viscisity with the cup again.

Thinning acrylic paint for airbrushing

Thinning acrylic paint for airbrushing is necessary to create a nice, smooth, and thin paint application. To thin acrylic paint for airbrushing you need to know the brand, the type of your airbrush, the sizes of needle and liquid nozzle, what air pressure use your type of airbrush, and be very specific about your plans for painting.

Thinning products for airbrushing come in different colors from transparent to opaque. It is a piece of important information because colored products can affect the viscosity. You have to control the ratio for thinning:

  • The opaque colors will be thicker and they need more reducer while thinning
  • The transparent colors are thinner and need less reducer or even need no thining sometimes

Please, make a note that thick, not thinned, or not properly thinned acrylic paint can damage and slow the airbrush, and alter the spray pattern.

What can I use to thin acrylic paint for airbrushing

With airbrushing you can simply use special airbrushing paints that already contain a thinner. Otherwise, there are 3 best options for thinning acrylic paint for airbrushing:

  1. adding distilled water
  2. using rubbing alcohol
  3. using airbrush thinners
thin acrylic paint for airbrushing

How to thin acrylic paint for airbrush with water

  1. Mix a 1:1 ratio of water and acrylic paint in a container.
  2. Shake vigorously for a minute or two or use a whisk.
Clean the nozzle every time before painting to avoid flakes

How to thin acrylic paint for airbrush with alcohol

Thinning acrylic craft paint for airbrushing with rubbing alcohol is an affordable way for everyone.

  1. Mix a 1:1 ratio and of rubbing alcohol and paint.
  2. Shake vigorously for a minute or two or use a whisk.

Using alcohol as a thinner has a side effect – an odor. Considering that, thin your paint in a well-aired room with gloves.

Clean the nozzle every time before painting to avoid flakes and cloging.

How to thin acrylic paint for airbrush with paint thinners

The best and most effective way to thin acrylic paint for airbrush is to use paint thinners or reducers. Usually, manufacturers create the whole product line, including paints and paint thinners.

The easiest way for you is just to find the paint thinner produced by the brand of the paint you use. Plus, the manufacturer will usually have full instructions.

The cheapest way to thin acrylic paint for airbrush is to make your own, homemade paint thinner.

Acrylic paint thinner for airbrush:

You can buy professional acrylic paint thinner for airbrush on Amazon and special art supplies online store like Blick Art

Here are 3 best airbrush thinners with prices and useful notes:

Brand nameNotePrice
Createx Colors 4012 High Performance ReducerWater-based premium reducer for thinning.
You can mix it with paint in any ratio depending on your needs.
$13.79 for 8 oz
Vallejo Airbrush ThinnerDilutes without loss of color adhesion, durability or consistency$13.25 for 200 ml
US Art Supply Airbrush Thinner Water-based acrylic paint thinning reducer and extender base.
Contains acrylic-based binders.
$15.96 for 16 oz

Homemade acrylic airbrush thinner

To mix homemade acrylic airbrush thinner for water-based paint, you can use distilled water, Fantastik all-purpose cleaner, glycerine, and isopropyl alcohol. If you decide to make a DIY airbrush thinner, be aware of what each component does:

  • A cleaner will dilute the paint. Be careful because using cleaners as thinner was not supposed by the manufacturer and usually they do not recommend mixing paint with the cleaner to preserve both paint and airbrush.
  • Glycerine acts as a lubricant and slows down the drying process.
  • Isopropyl alcohol allows the paint to flow freely, but also can break the paint and affect
2 DIY acrylic paint thinner recipes:

Recipe #1: The easiest recipe is just to mix 3/4 of distilled water with 1/4 of Fantastik all-purpose cleaner.

Recipe #2: mix 2/3 of distilled water with 1/3 of isopropyl alcohol and add 1 drop of glycerine per every 50 ml of the thinning mixture, e.i. if you have 50 ml of isopropyl alcohol, 100 ml of water, your mixture is 150 ml and you add 3 drops of glycerine.


How to thin acrylic paint for pouring

The pouring medium was specifically designed for acrylic pouring, it improves the flow and does not affect pigments or color intensity.

The optimal ratio is 1:1 pouring medium to paint.

The best consistency is similar to honey.

Pouring mediums you can use: Liquitex Professional Pouring Effects Medium, Golden Artist Colors Color Pouring Medium, DECOART Pouring Medium, Floetrol.

Here, in one of the sections below, I sum up best acrylic thinners for you with prices and notes.


14 Best acrylic paint thinners

Gently remind you that the best way is to choose paint thinner of the same brand as your paint. This is why I’ve tried to mention all popular and tested brands in following table.

acrylic paint thinner
ProductUseNotePrice
Liquitex Flow-Aid Fluid AdditiveFlow Improver​100% acrylic polymer emulsion.
Increases the flow, absorbency, and blending of any water-based paint, ink, or dye.
Can be used in airbrush too.
Recommended by Liquitex for watercolor effect.
$6.92 for 4 oz
Winsor & NewtonFlow ImproverFlow Improver​Maintains the stability and strength of the color and slightly slows drying.
Effective for hard edge painting techniques.
Increases the flow of acrylic colors.
$11.79 for 4 oz
Mont Marte Premium Acrylic Flow MediumFlow Improver​Highly versatile.
Increases the translucency of acrylic paints without affecting their color intensity and vibrancy
$8.99 for 250 ml
Golden High Flow Acrylic PaintThinnerReduce clogging in small tips-nozzles.
Works on paper, canvas, for airbrush, calligraphy.
$26.52 for 16 oz
Reeves Artist Painting MediumThinnerIt thins acrylic paints and increases flow.
It enhances adhesion and durability and increases transparency, intensity, and gloss.
$8.39 for 2,5 oz
Createx Colors 4012 High Performance ReducerAirbrush reducerWater-based premium reducer for thinning.
You can mix it with paint in any ratio depending on your needs.
$13.79 for 8 oz
US Art Supply Airbrush Thinner Airbrush reducerWater-based acrylic paint thinning reducer and extender base.
Contains acrylic-based binders.
$15.96 for 16 oz
Vallejo Airbrush ThinnerAirbrush thinnerDilutes without loss of color adhesion, durability or consistency$13.25 for 200 ml
Chroma Fusion I.A. Series Pro-Grade Binder MediumAcrylic binderOffers superior adhesion. $36.68 for 16 oz
PEBEO Studio Acrylics Auxiliaries, Bindex Acrylic binderNon-yellowing, liquid binder with a translucent, glossy film.
Gives acrylics depth and brightness
$25.59 for 1L
Liquitex Professional Pouring Effects MediumPouring MediumContains acrylic polymer. Creates easy paint flow.
Glossy.
$26.49 for 16 oz
Golden Artist Colors Color Pouring MediumPouring MediumLow crazing extender for pouring acrylic colors. Glossy.$19.64 for 16 oz
DECOART Pouring MediumPouring MediumPremium quality with the best consistency.
Preserves the brilliance of the colors.
Quick-drying, cracking free.
$61.99 for 16 oz
FloetrolPouring MediumTo use only for pouring.
It is a latex paint conditioner.
It thins and strengths the qualities of latex paint, improves the coverage.
$27.96 for 1 gal

3 Extra Tips on how to paint with thinning paint

Sometimes, even if we had images in our heads or on sketches, the real painting, colors, and shades don’t look as we wanted.

If the results do not meet your preferences, try this:

  1. Use a primed surface. The best way to prime your surface is to use gesso. Gesso will provide perfect paint adhesion and color vivacity. To learn more about when gesso is necessary and discover the 11 best gesso, you can read my article about gesso.
  2. Use the right brush for thinning. The wide brush can be better if you cover a big surface.
  3. Use the fat over lean method. This method suggests painting in layers: every new layer should be thicker than the previous one. The fat over lean method is the basic principle of the painting and protects your work from cracking and peeling.

Does thinning paint change the color?

The thinning does not change the color. But if you thin paint with water, remember that water dilutes the paint and lightens its color. In this case, apply additional coats of paint.

How to soften hardened acrylic paint?

If your paint has fully dried, nothing will help. If you left you paint for a while and it became thicker and harder, try this:

  1. Add acrylic binder and some water.
  2. Stir
  3. Paint again 🙂