The Artful Chemistry of Acrylic Pouring
Posted By Central Art
The Art & Science of Acrylic Pouring
As I started researching the science behind acrylics, the ‘do’s and don’t’ s of acrylic pouring, and eight (hand-written) pages later, I realized that I would need to do this blog in at least two parts. So, I will first address some of the more frequently asked questions we get in the store and workshops with relatively short answers, then if you are interested in understanding more about the chemistry and science behind a successful (or unsuccessful) pour, read on McDuff!!😁
FAQ’s
Q: Do we sell artist-grade silicone oil?
A: No. There is no such thing as ‘artist-grade’ silicone oil. We do not sell or endorse the use of silicones (any form) in
acrylic pours as the manufactures of artist-grade acrylics and acrylic mediums do not recommend their use.
Silicones do not dry and can compromise the integrity of the acrylic film and adhesion properties, including
cracking, peeling, sloughing, or not fully curing (drying).
Q: Do we sell Floetrol?
A: No. Floetrol is a paint conditioner meant to be used with latex house paint. It has not been tested by the makers
of Floetrol or artist-grade acrylics to determine what the long term effects of the Floetrol might have on the integrity of
the film formation or adhesion properties of the layers.
Q: What about the other products seen on YouTube that are not silicone or Floetrol (like hair care products, coconut or olive oil, dish soap, etc.)?
A: The answer is the same. Non-drying oils of any kind are not recommended for the very reason they do not dry
and can become trapped between the layers or prevent the acrylic from fully curing. The same can be said for soaps.
(And just an FYI, the popular coconut oil hair product seen in many of the YouTube videos has a type of silicone
as it’s first ingredient 🤷🏼♀️It is more likely this than the coconut oil that creates the cells.
Q: What can I add to my to acrylic paints and pouring medium to create cells and maintain the integrity of the pour?
A: Manufactures like Golden and Liquitex recommend using 70% isopropyl alcohol. The alcohol is less dense than
water & evaporates quicker so it is not left behind in the paint or pouring medium. It can be mixed in, dripped,
splattered, or sprayed. You can also add alcohol inks. The Titanium White, metallics, & interference* colors are
opaque & lightfast. (*Ranger - Snowcap, Marabu - Rainbow, Piñata - pearl). These can also be mixed in, dripped,
or spattered. It is not recommended to spray (aerosolize) alcohol inks or blending solutions. They have
components that can be harmful if aerosolized and inhaled. Golden recommends as a starting recipe; 2 parts Pouring
Medium (GAC 800): 1 part High Flow Acrylic: 1 part 70% isopropyl alcohol. Using too much alcohol can cause
the pour to no cure.
Q: Are there other ways to create cells?
A: Yes. How you layer the paints can create cells. Each pigment has it’s own density (weight) heavy pigments sink &
lighter pigments rise. As these move through each other and/or the pouring medium they create cells. Swiping a
heavier paint over the lighter pigments also creates cells.
This may sound complicated but Golden Paints has a pigment density chart (goldenpaints.com). Go to
Resources - Tech Info - Application Sheets (Pigment Density). These can basically be applied to other
professional-grade acrylic paints.
Q: I see people using a kitchen or resin torch on acrylic pours - what are they doing?
A: Some people are using them for cell creation, others to pop air bubbles.
This is another technique that is not recommended by the manufactures of acrylic paints. These torches can reach
temperatures of 1,400 - 3,600 degrees F. Even just “kissing” the wet paint and mediums can release chemicals that are
harmful if inhaled. The heat could also effect the film formation and/or adhesion properties of the paints or medium.
Many of the materials seen being added to pours, like silicones and alcohol, are flammable & could cause a fire or
harmful inhalants.
Q: Do I really need to use professional-grade paints and mediums? Can I use student or craft paints?
A: No. You do not have to use professional-grade paints or mediums, but they do have advantages over student &
craft-grade paints, so if you plan on selling or gifting your pouring art you probably want to use the professional-
grade paints. Student & craft-grade paints have a lower pigment load than the professional-grade & many of the
more expensive pigments are replaced by less expensive pigment combinations to approximate the expensive
pigment hue. These paints may also be less lightfast (fugitive) than the professional-grade paints.
Q: Do I need to use acrylic pouring medium? I see people on YouTube & pouring websites using Floetrol, Elmer’s Glue, house paint, etc.
A: Again, these are not really art materials & they will not give you the same results. Acrylic pouring medium has
been specifically formulated for pouring & acrylic paints. The acrylic pouring medium will not negatively effect the
adhesion or film formation of the paint.
Q: If I want to use Floetrol to make cells can’t I just use house paint for pouring?
A: Of course, you can use house paint if you wish. But since Floetrol is a latex paint conditioner it likely won’t make
cells. If it would, it would make cells on the side of your house or on your walls 😉 (wouldn’t that be cool!) 😄
Acrylic has advantages over latex. Even though Latex has some acrylic polymers it also has vinyls and other materials.
Latex is less flexible and the pigments are not as lightfast as acrylics.
Q: How much paint and pouring medium do I really need to use? It seems like people on YouTube and pouring
websites use a lot.
A: If you are using professional-grade paints and pouring medium you actually need very little paint. A recommended
ratio is 1 part paint to 10 parts pouring medium. If you are using student or craft-grade paints or other materials like
Floetrol or silicones then you will need to experiment to get the ratios right.
Q: Is it OK to use heavy body paints?
A: Yes, but they will need to be thinned, otherwise they cannot flow. Thinner paints such as Golden Fluid & High
flow or Liquitex Soft Body & Inks (or their equivalent viscosity) work best.
Q: Can I just use water to thin paints? I also see people using water to create cells? How much should I use?
A: Short answer is yes, you can thin acrylics with water. Longer answer, is that you can thin the acrylics with water
because it is a solvent for acrylics so using too much can effect the integrity of the paint. The manufactures of
acrylics recommend using no more than 25% water to thin acrylic paint. The cells probably occur because the
acrylic polymer particles cannot adhere together or form a cohesive film. These cells will likely continue to pull
apart as the paint cures.
Q: What can I use instead of water to thin thicker paints?
A: There are several options. Many of the Golden Fluid Mediums such as GAC 500, GAC 100, Polymer Medium, Fluid
Matte or Gloss Mediums or Liquitex Fluid Mediums can be used, or thinner paints or acrylic inks can be added to thin
down the heavier paints.
Q: I get air bubbles. Why? How do I get rid of them?
A: Shaking to blend the paints and pouring medium or vigorous stirring can cause air bubbles. The best method to
blend the paints & pouring medium is to gently stir until blended & then allow the mixture to settle for 4-24 hours.
Air bubbles can also occur as the paints move through each other. You can pop the air bubbles with a needle or
pin as they form.
Q: How long does it take for a pour to dry?
A: There are several factors that determine the dry time. How thick the pour is, the support the pour is on, humidity,
temperature, etc. Just like any other acrylics, they may be dry to the touch but not cured. Acrylics dry as the
water & other volatilates evaporate and the acrylic polymer particles come in contact with each other & adhere to
one another.
Q: Why does my pour look different after it dries?
A: There are a couple of things that happen to acrylics as they dry. First, they dry a little darker. So it is good to
use colors of varying values. Secondly, even though the pour may be dry to the touch, all the layers may not be
fully cured, so the layers may continue to move until they are fully cured. This is why it is very important to make
sure your pour is on a level surface. If it isn’t, you might loose some of the cool elements of your pour.
Q: Can I paint on top of a pour?
A: Yes. Once a pour is cured (give it a good 24-48 hours) you can paint acrylics or oils over a pour. However, you may
need to do a little prep first. If the pouring medium used dries with a gloss or high gloss finish, you will need to use an
acrylic matte medium or matte fixative or clear acrylic gesso over the pour before painting. This will give the paint
something to attach to.
You can also pour over a pour. So if you are not happy with how a pour, or part of a pour, turns out you can pour over
it.
Q: What surfaces can I pour on?
A: Smooth, non-flexible surfaces like Ampersand Smooth Pouring boards & Ampersand Clayboards, glass, or metal are
great for pouring, especially larger pours or when using a lot of medium/paint. You can pour on canvas and other
textured surfaces but the paint will move differently and it can create interesting patterns. Stretched canvas is OK to
use but it is not recommended for larger pours as the canvas can sag in the center under the weight of the pouring/
paint mixtures and run to the center of the canvas.
Q: What is an acrylic skin? How do you make one? What do you use it for?
A: An acrylic skin is a pour done on a non-porous surface, like glass, metal, or certain types of plastic, that once dry can
can be peeled off. Acrylic skins have many uses. You can make window clings, cut them into shapes or pieces for
collaging, jewelry, etc. They can be adhered to canvas, wood, metal, plastic, glass, ceramic or porcelain. You can use
gel mediums as a glue.
Of course, I haven’t answered all the questions, so please feel free to ask any questions you may still have about his subject, or any subject. You can ask on Central Art’s Facebook page, or email me directly at lara@centralartsupply.com
Part II
After watching hours of acrylic pouring on YouTube and seeing all the “stuff” people are adding to pours I contacted Golden, Liquitex, and M. Graham to ask what could be and what should not be added to acrylics and pouring medium. I also did a lot of research into what acrylics are and how they work. Understanding how a product works can make using it easier and can help you get the best results.
There is a really good article on pouring through Golden Paints. (goldenpaints.com) Their Just Paint article, (justpaint.org) ‘Understanding the Techniques of Pouring Acrylics’, is a great resource, especially the Q&A section.
So, now let’s get technical and break down the components of an acrylic pour.
Let’s start with what acrylics actually are. Most people think acrylics are water-based paints. I did, before researching this article. Acrylics are actually chemical-based paints that are water solvent. What does this mean? The definition of acrylic paint is, ‘a fast drying, finely balanced dispersion of pigment suspended in an acrylic polymer and water emulsion’. Acrylic paints are water-soluble when wet and a water-resistant plastic film when dry. There are 3 primary components in any acrylic paint: Pigment, Binder, and Vehicle. Pigment refers to organic or inorganic, natural or synthetic granular solids that are milled to tiny particles that do not dissolve, but remain suspended, in the acrylic polymer/water emulsion. Pigments have little or no adhesion properties of their own. Binder refers to an acrylic polymer emulsion that forms water-resistant a film when dry. Vehicle refers to the part of the paint that carries the pigment and binder. Water is the vehicle (and solvent) for acrylics and when combined with the binder it creates a polymer emulsion that allows the paint to remain wet.
Now let’s talk about how acrylics dry. Acrylics (paints and mediums) dry through the evaporation of the water and certain volatilates from the emulsion. As these elements evaporate, the acrylic solids move closer together, eventually coming into contact with each other & forming a film. As these compress together with enough force to expel the water and volatilates they coalesce into a cured film that is quite stable and unreactive to moisture or additional paint layers.
Now for the acrylic pouring medium. Acrylic mediums are basically the same as the paints minus the pigments. Mediums have different additives to create different properties, but the binders and vehicles are the same. Acrylic pouring medium reduces crazing and modifies or extends paint for pouring, improves flow & adhesion, & keeps the colors separate with minimal to no blending. It also slows the dry time so you have more work time. Acrylic pouring mediums from different manufactures will have some variances, such as viscosity, sheen, and clarity, but the basic properties are the same.
To Add or Not To Add, that’s is the question.
Because the acrylic pouring medium keeps the paints separate it allows the different pigments to create layers. This is important in understanding why certain types of additives can cause those layers to fail. Also, keeping in mind how acrylics dry, if non-drying additives, like silicones, Floetrol, and oils, get trapped between these layers then the layers cannot adhere to each other or create a stable film and can continue to move, over several days or even months! These products create cells because they repel the paint and medium. Some of the products, like silicone oil, rise to the top of the pour and will sit on the surface as the top layer tries to form a film. This oil needs to be wiped off, sometimes frequently over a period of several days or weeks. There is no way of knowing if all the oil makes its way to the top and any that is not wiped off could cause adhesion issues for varnishes, added layers of paint, or resins. Silicone oil is also flammable and could cause serious harm if torched.
Even though many people out there are using these products, they typically do not show their failures or long term results.
As artists we like to experiment and try new things. If you are interested in trying some of the things you see on YouTube, by all means experiment away!! You might not want to use professional-grade paints and mediums for cost reasons, but we do have less expensive artist-grade alternatives. If you are going to use non-professional materials or materials not recommended you might want to scan or photograph your pours while they still look the way you like them in case the pour eventually fails or changes to a less desirable form. If you are going to sell, gift, or show your originals, or you just want to decorate your own walls, you will likely want to use professional materials.
Whatever you decided to do, have fun and be creative!!
Keep an eye out here for future blogs or answers to your and other customer’s questions.
Central Art Supply
Sharing your passion for art!
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