An Introduction to Acrylic Paint Mediums

Acrylic paints are made to be thinned with water, but if you add too much water you run the risk that there's not enough binder in the paint for it to stick properly to the canvas or paper. Acrylic mediums intended for thinning paint basically consist of the binder used in acrylic paint ("colorless paint") and so ensure the paint will stick.

Some glazing mediums seem milky white but dry clear without changing the color. If in doubt, do a test before using it on a painting.

See Also:
• How Much Water and/or Medium Can You Add to Acrylic Paints?
• How Thick Should You Use Acrylic Paint?

How thick acrylic paint is when its squeezed from the tube depends on what brand it is (it can vary from a soft buttery consistency to quite stiff) and what type (this ranges from fluid, soft body, to stiff). There are a lot of mediums you can add to make the paint thicker so it retains texture created by brush or knife.

Texture mediums can be mixed with paint or applied as an initial layer you paint over. Some texture mediums have additives to create extra or specific texture e.g. sand, glass beads, or fibers. Some texture mediums are gels that dry to a clear, glossy finish. Others are dry to a coarse, matt finish. Some are designed for carving into. Check the label to see what to expect.

If you want to break the consistency of acrylic paint to make a very fluid or runny paint, add a dispersant medium. It creates paint that's perfect for staining and pouring techniques.

See Also:
• Is it Okay to Paint with Acrylics on Raw Canvas?
• Example of a Painting Done by Pouring

Acrylic paint can be used without adding any medium for fabric painting but to prevent the result from being stiff, add a fabric painting medium. The paint will need to be heat set if you're going to wash the fabric; this can be done with an iron (check the safety instructions on the bottle and work in a well ventilated space).

See Also:
• Product Review: Golden GAC900 Fabric Paint Medium
• Mediums for Silk Painting with Acrylics

There are a number of acrylic mediums produced for using with decorative painting to get particular paint effects. For instance, cracking medium is used to deliberately cracking a varnish or layer of paint to get an aged effect. Marbling medium is used to stop paints mixing together, producing swirls of unmixed color. Antiquing medium is used to make something look old and worn at the edges.

To get the best results with these types of acrylic mediums, take the time to read the instructions carefully before you start. With some it's just a matter of adding it to the paint, but with others there's a sequence you need to follow to get decent results.

Although gesso isn't strictly speaking a medium in that you use it before you paint, I'm including it here because it's generally on the same shelves in an art-supplies store as acrylic mediums. A 'normal' gesso is designed to be the initial layer on a support, whether it's canvas or board. It both protects the support and provides a good surface for the paint to adhere to.

Various gessos are available, so check the label to see what you're buying. The most commonly formulation is a gesso that dries white, but you get some that dry transparent or have a color in them (such as black) to create a colored ground.

See Also:
• You Need to Gesso a Prestretched Canvas Before Using It?
• How to Prime a Canvas

Although varnish isn't a medium but a final protective coating for a painting, I'm including it here because it's generally on the same shelves in an art-supplies store as acrylic mediums. Some artists do use varnish as a medium, but it's does carry a potential risk if the painting is cleaned at some stage in the future. If a conservator removes the final coat of varnish and the layer of paint immediately below it is mixed with some of the same varnish, there's the risk that some paint will be removed too.

See Also:
• Why Varnish a Painting?
• How to Varnish a Painting
• Know Your Brushes: A Varnishing Brush

Golden Artist Colors have a range of acrylic mediums which enable you to use just about any fairly flat surface as a printing surface in your ink-jet printer. Great potential for mixed media and producing prints of your paintings on specialist paper.