Viscosity of Acrylic Paint

Learn types of Acrylic Paint Viscosity in detail. Heavy Body vs Soft Body acrylics and its usage. Fluid Body and Ink consistency acrylic paints

Painting is not just about colors but choosing the right type of paint is vital for good result. To cater the need of a various applications, acrylics are available in different consistency or thickness, also known as viscosity. They are sold in jars (heavy body), tubes (soft body), and bottles (high flow inks).

Each viscosity is designed for specific use. For example heavy body paint is ideal for impasto and texture work; soft body paint is used for blending and continuous brush work; fluid paint is suitable for acrylic pouring. The paint's viscosity will decide how much pressure you must apply on the brush to slither across.

For example, take a plate and drop some high viscosity paint on it. Take another plate and drop some low viscosity paint in this one. Flip both the plates at the same time and see which paint drops first. As expected, low viscosity paint will fall faster. Consistency and gravity both play their roles.

Viscosity, sheen, and opacity of paint must be considered when buying paints for your artwork. Let us get familiar with these terms. 

Acrylic Body Paint is broadly divided into three types:

High Viscosity Acrylic Paint is a heavy body

Medium Viscosity Acrylic Paint is a soft body

Low Viscosity Acrylic Paint is high flow ink

Each paint viscosity is designed for specific painting techniques. Choose one based upon the style and methods you will use. Initially, you may find it challenging to select, so read below to find out when and how to use these acrylic paints.

Acrylic consistencies:
  - Heavy Body Acrylic
  - Soft Body / Open Acrylic
  - Fluid Acrylic

Heavy Body Acrylic

Green color Heavy body acrylic paint

This paint comes in a jar or tube, has a creamy consistency and a thick viscosity like butter. The tube varieties have a tendency to be like toothpaste or perhaps mustard when squeezed from the tube. They can still maintain their shape but are ready to be dispersed evenly. 

Heavy body acrylic paints have no fillers, dyes, extenders, toners, or pacifiers added. They are in their pure form, and hence the colors are vibrant. Of all of the available viscosity, heavy body acrylics give excellent coverage.

They create good peaks making them well suited for impasto methods. It allows you to sculpt the paint and build up layers of rich color and texture. Once dry, the acrylic polymer braces the material, adding texture and bringing a 3D aspect into the work.

Because of their expressive nature and high viscosity index, they are useful in various applications. Mediums can be used to thin or thick the paint without affecting their glaze and shine. 

Heavy body acrylics are excellent for artists who like oil paint but cannot wait for the drying period. When painting using acrylics, multiple layers of varying thickness are implemented in sequence. Next coating is applied when the prior will be a bit dry, unlike with oil painting. 

Ideally used for:

  • Palette knife painting
  • For nearly 3D effect 
  • Impasto layers, in which the brushstrokes are apparent

Soft Body Acrylic

Soft Body Acrylic Paint

Soft body or Fluid acrylic paints have similar intensity as the heavy body but flow evenly like a thick cream. Due to the same viscosity and pigment load as heavy body, it has the same glaze, shine and purity. 

Best suited applications are dry brush, detailing, pouring, and primary artwork. They are flexible and mix well with other acrylic paints like heavy or fluid. When you have to blend paints on the canvas or wish to make changes to an existing one, they are reliable.

Ideally used for:

  • Fine detailing work
  • Glazing
  • Staining
  • Dry brush or spraying

High Flow / Acrylic Ink 

Acrylic Ink

High Flow Acrylic has an ink-like consistency, extremely fluid with the lowest viscosity index. They are water-based, highly pigmented, and very useful. The film formed on the surface is water-resistant.

Acrylic ink is perfect for a painting technique called Glazing. The glaze is made by adding paint  any transparent medium or water to the paint. The paint to medium ratio is somewhere around 2:8. A small amount of paint is mixed with a large amount of medium. There are many high flow mediums available for this technique, but many prefer to use just water. The glaze is applied on smooth canvas or a water-color paper to get the best result. Many transparent layers are used to create the glazing effect.

These acrylic paints can be used in form of brush, markers, dip pen, and airbrush. The brush marks are not visible with free-flowing fluid acrylics. Acrylics are used in a various techniques, including staining, leveling, calligraphy, mixed media, fine line and broad strokes. Artists create stunning art using this paint due to its versatility. 

Ideally used for:

  • Watercolor effects
  • Stamping
  • Airbrush, dip pen, calligraphy

General Tip:

You can mix different types of acrylic body type paint together to achieve the desired consistency. There are many gels and mediums in the market that can be used to get the correct viscosity.

Artists also use multiple types of viscosity in a single painting. You need to make a logical choice for your work. It will help you make the most of the acrylic paint. 

A beginner can start with soft body acrylic, as they are easy to control. Hope this post gave you a little insight into the viscosity of acrylic paints!