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3D Acrylic Painting Techniques Blog

Blog > Acrylic Mediums Explained

December 24, 2014 - by Ruth Collis

Acrylic Mediums Explained

Confused about the plethora of acrylic mediums out there? That's because there's been such an amazing growth in the technology of what paint can do now, as well as each manufacturer changing the name of the same thing for their own. These mediums are the key to all the fun 3D acrylic painting techniques you can apply with them.

Mediums for the thick painting world

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Gesso helps the paint stick to the canvas better because it's a bit toothy, rough, and porous. Canvases come already primed with gesso now, with 2 or 3 layers so that you don't have to do this and is just ready to paint. Smooth panels would need sealing and then gessoing, or canvas material that is raw or uncut and you want to stretch it yourself. There are different colored gessos now which provide a good base for a certain scene you want seen in that hue.



A glaze is a thin coat of transparent paint color. Adding a clear medium will help spread it evenly.



Liquid paintings are more popular now and have some variations how you can use acrylic medium. You can use just use fluid paints without watering down the binder so that they stick well to the support. Paint color can be added to fluid mediums that make the paint thicker, more flexible, extend the paint's use, flow better, prevent crazing, and can pick up many painted designs for an easy transfer to another surface. 


Liquitex Pouring Medium
Golden Self-Leveling Medium
Tri-Art Self Leveling Gel 


String Gels
As the name implies, the acrylic gel medium medium is stringy like honey; however, it does not dry that way, with a raised rounded edge. It self-levels, which means the string flattens out.


Liquitex String Gel Medium
Golden Clear Tar Gel



Impasto means thick application of paint. This is what has made the whole world of thick sculptural painting come alive in the most recent years from gels to pastes. It comes in many forms of smooth to textured, and what enables seeing many wonderful brushstrokes and texture in a painting. Some have paint color already added and some come without color and in bulk quantity that enable savings. Textures of Pummice, Glass Beads, Crackle, Crystal Mortar, Light Molding Paste, and Spider Web Paint are just a few of this exciting frenzy to discover!


Gels vs Pastes
Gel mediums come milky white and dry clear. Their advantage is being able to add paint color before they dry to have a beautiful mixture of colors. Pastes are white or gray and you can add color, but some brands dilute the color, like adding red will result in a pink when mixed with a paste. A paste is useful for a texture they might bring, or some are sand-able when dry. Color is then best applied after the paste is dry, a 2nd separate process.


Nova Color 209 Super Gel
Liquitex Super Heavy Gel Medium
Golden Extra Heavy Gel Gloss

Artist's Loft Super Heavy Gel (4 ounces for $3.99 at Michael's)



Nova Color 250 Coarse Lava Gel
Golden Pumice Gel Coarse


Glass Beads
Liquitex Glass Beads 
Golden Glass Bead Gel

Kroma Crackle
Golden Crackle Paste 


Crystal Mortar
Pebeo Crystal Mortar


Light Molding Paste
Golden Light Molding Paste

Liquitex Light Modeling Paste


Spider Web Paint
Montana Spider Web Paint

Slow Drying
This is where you would like acrylics to perform more like oils so that you an have more time to work with it. This is called "open time." To dry acrylics more slowly, you would add a slow dry medium, or retarder to the paint. Golden has a whole line of paints with slower drying open time to where you don't have to add anything, called: Golden OPEN Acrylics Set.
Liquitex Slow-Dri Medium
Golden Acrylic Retarder Medium
Nova Color 299 Acrylic Retarder




Speed Drying
To dry acrylics faster than they already do is called using a blow drier! Yes, there are many times you will want to dry acrylic paint even faster. Do not use a fan or forced-air on Pouring Medium, especially in puddles, or it could dry with ripples.




Shine (Matte/Satin/Gloss)
You can get most of these mediums above in various levels of shine. Gloss is shiny, matte medium is not shiny, and stain is a mixture of the two, not glaring from shine, and not flat matte, but a little sheen, thus called satin. Gesso is not available in gloss because gloss usually is slippery. Matte is not and you want your paint to stick to the canvas, and since you paint over it, there is no need for gesso to be glossy.




A clear coat is needed in acrylic varnishing to protect paintings from dust, kitchen grease, moisture, people smoking, incense, expansion and contracting of heat and cold, and some have UV sun protect-ants in it to keep a painting from fading. Some acrylic varnishes are removable, which helps a conservator to remove this grime over time and help renew a painting to it's original state. Some varnishes come as brush-on which leaves more shine, but sometimes brushstrokes, and others as a spray-on varnish, which an be easier to apply but fumes being very smelly. Perfect Paper Adhesive actually has a gloss that dries non-tacky, with some UV protection, and a neat pour-able bottle, but is pricier. Most manufacturers have several varnishes in their line from glossy to matte:


Nova Color 206 Gloss Medium & Varnish
Liquitex Gloss Varnish
Golden Gloss Varnish with UVLS
Perfect Paper Adhesive - Gloss
Perfect Paper Adhesive - Matte


With all the art mediums out there, it can be a little overwhelming. Just try one at a time to learn about them.

Which is your favorite medium?

Answer in the comments below.

Ruth Collis, Sculptural Painting Instructor

Ruth Collis

Sculptural Painting Instructor

Start with the Basic thick sculpting medium of them all, covered in this free video course: how to paint a Simple Sculptural Rose, and also learn how to save great money on the cost of gel mediums and get 3 times as much than what is sold in the stores.

How to Paint a 3D Simple Sculptural Rose free video course by Ruth Collis
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