Learn How To Choose Acrylic Paints
There's a lot to learn about art supplies! Through this series of articles, our aim is to provide fundamental information to help you find the art supplies that best fit your goals.
In this edition, we'll be covering how to choose acrylic paints.
What are Acrylic Paints?
Acrylic paints were developed in the 1940’s as a painting medium that combined the properties of watermedia and oil painting.
They are a versatile medium that can be painted on virtually any non-greasy surface like paper, primed or unprimed canvas, and masonite board.
Acrylics can be used with wet techniques, can be applied thickly without cracking, and are great for applying multiple layers quickly. They are water-soluble, flexible, permanent and will not yellow with age.
Types of Acrylic Paints
Acrylic paint consists of pigments suspended in an acrylic polymer emulsion. They are a quick-drying paint, depending on the thickness of their application. The viscosity of the paint varies depending upon the manufacturer and the forms they are produced in.
There are a few common forms of acrylic paints. The name for each form may vary per brand, but they tend to fall in similar categories across the board.
Heavy Body Acrylics
Heavy body acrylics are high viscosity paints that provide a thick and buttery consistency. Great for multiple layers of application.
Fluid Acrylics
Fluid acrylics are low viscosity acrylics that have the consistency of heavy cream. They can be washed on, brushed, poured, applied as a stain, or sprayed. They are self-levelling which enables them to dry flat with minimal brush marks.
Liquid Acrylics
Liquid acrylics are ultra-low viscosity paints that provides full colour intensity while remaining transparent. These are often also called acrylic inks. They can be applied with a brush or directly out of the bottle. These liquid acrylics are suited for fine detail work when added to refillable markers and pens, and are also perfect for airbrushing.
Controlling Viscosity with Acrylic Mediums
The viscosity of any acrylic paint can be altered with the use of acrylic mediums and glazing liquids. It is ideal to start with the viscosity of paint closest to what you are looking for. Fluid or liquid acrylics when you need a lower viscosity paint, Heavy Body paints for a higher viscosity.
When thinning heavy body acrylics with water, they should not be thinned down more than 50 percent as, once diluted, the paint’s adhesive properties are weakened.
That said, adding water to thin down heavy-bodied acrylics is generally not advised. Instead, acrylic mediums and glazing liquids can be used to ensure that the adhesive properties of the polymer remain intact.
Professional vs Economy Grade Acrylics
Professional (Artist) and Economy (Student) grade acrylic paints use the same binder or acrylic emulsion to suspend the pigment. What differs between these grades of paints are the pigment load and use of fillers.
Professional acrylic colours contain both synthetic and genuine pigments of the best quality to ensure rich colours and permanency. They also contain a much higher load of pigment than economy paints which results in better coverage and density of colour. Some professional grade colours will tolerate a higher pigment load than others due to the size of the pigment molecules. As a result, these colours tend to dry more opaque and with a matte finish. The artist grade colours that have a slightly lower pigment load dry to a glossy finish and tend to be more transparent.
Economy paints are formulated to keep the price low for the beginning artist. The most effective way to do this is by reducing the amount of pigment that you would find in a professional paint by about half, and/or using a synthetic hue instead of a genuine colour. With less pigment overall, the bulk of the paint is made up by additives such as fillers or stabilizers, meaning the colours strength will be lessened and the use of more paint will be needed.
What are the differences between Acrylic & Oil Paints?
The most noticeable differences between the two are the drying times and appearance of colour.
Oil paints dry much slower than acrylics and although retardants and atomizers can be used to slow down their drying time, acrylics have their own distinct working properties. Golden OPEN Acrylics are unique paints that eliminate some of the working differences between the two, primarily drying time.
In terms of colour, linseed oil molecules are much smaller than acrylic polymers, enabling oil paints to carry a heavier concentration of pigment. This results in a noticeable difference in the way colour appears when dry. Linseed oil is transparent, both when wet and dry, which means that the appearance of the colour when first applied will be the same when it dries.
Acrylic colour, on the other hand, appears lighter when wet because the polymer which carries the pigment is milky and translucent. When the paint dries the emulsion becomes clear and thus the pigment is seen more clearly and appears to be darker.
These differences do not indicate that one medium is better than the other, instead they just illustrate that oil and acrylics behave differently.
Can I mix different brands of Acrylic Paints?
Although acrylic paint formulas are generally the same, they do contain different additives. Since acrylics contain water, they need a preservative such as ammonia or formaldehyde to prevent mould. Thus, these paints are not considered non-toxic and should still be used in a well-ventilated area. Economy paints like Chromacryl and LIQUITEX Basics are considered non-toxic as they do not contain the same toxic preservatives.
Acrylics also include surfactants that enables them to disperse in water, defoaming agents to reduce the foam the surfactants produce, and wetting agents to increase pigment flow. Consequently, some qualities of paints may not work well with others. Acrylic painting is a comparatively new medium and the long term effects of combining different brands is unknown. If you are going to mix different paints be sure to test them first and to use brands of comparable quality.
Specialized Acrylic Applications
Airbrushing Acrylics
Liquid acrylics have a smooth consistency and high pigment load which makes them ideal for use with airbrushing. They offer a wide colour selection, are permanent and flexible, and are easy to thin with either water or air brush mediums for a sprayable consistency.
When airbrushing onto a porous surface such as absorbent paper or unsized cloth it is best to thin acrylics with water. A porous surface will absorb the thinned acrylic and allow it to permanently surround and thus stain the fibres of the support. Add up to 50% water and mix thoroughly, to facilitate the flow through the airbrush.
Different colours will require more or less water depending upon the pigment load or concentration. When air brushing onto a non-porous surface or primed canvas it is better to thin with an air brush medium to ensure with an air brush medium to ensure that the paint adheres to the painting surface.
Fabric Painting with Acrylics
Acrylics can be used on virtually any fabric including cotton, cotton/poly blends, woven, felt, terry cloth, silk, velvet, corduroy and flannel. The wide variety of colours and availability of opaque to translucent paints allows the artist to achieve varied results. Acrylics dry as a result of the evaporation of moisture, so no heat setting, steaming or chemical fixing is needed for permanency.
We strongly recommend testing fabric to ensure the compatibility of the fabric and your technique. It is important to pre-wash new fabrics to remove all sizing which might otherwise interfere with the adhesion of the paint and to take care of any initial shrinkage of the fabric. Also, remember to protect the surface under your fabric by placing cardboard, plastic or wax paper on the surface or against the back of the fabric. This will help to ensure that the fabric does not stick to your working surface or to another piece of the fabric, as in the case of t-shirts.
Fluid acrylic colours are great for lightweight or textured fabrics, while heavy-bodied paints are excellent for heavier fabrics or for thicker impasto techniques. If fluid acrylics are unavailable, thinning the heavy-bodied paint with a medium will reduce its stiffness and increase flexibility so that it works with the fabric like a fluid paint. If you wish to use acrylic paints for silk screening techniques on fabric be sure to mix your paints with a silk screening medium so that the paint does not dry permanently on the screen.
Mural Painting with Acrylics
Professional quality acrylics are one of the most durable watersoluble paints available. These paints have been proven to last for many years under a variety of conditions when applied properly. Acrylics are chemically alkaline and are compatible with such common mural grounds as concrete, plaster, cement and concrete block. As well, acrylics contain no toxic solvents, nor require toxic cleaners, and they mix with water. They dry quickly to a permanent waterinsoluble finish.
Economy quality acrylics are not recommended for mural painting as their colours are less permanent and the paint film is not as durable. All mural painting surfaces must be prepared and clean of any dirt or grease before painting.
Marbling with Acrylics
Marbling with acrylic colours is one of our staff and customer favourites. By using a marbling medium, acrylic paints and a bath of kelgin and water, you can marble objects such as paper and fabric. See our handout “Marbling on Paper with Opus” for further information on this application of acrylic paints.
Stenciling with Acrylics
When using ready-made or personalized stencils, acrylic paint can be applied with a foam dabber, rag or stencil brush. To keep your lines clean use the paint straight from the tube or jar. Do not thin the paint as it may to spread and bleed under the stencil.