Acrylic paint is a popular, all-purpose medium that should be a part of every crafter’s toolkit. It is also a suitable medium for clay surfaces and can bring a project to life. However, sometimes projects don’t turn out the way we hope – sometimes paint can peel from the clay surface.
Here are three reasons why acrylic paint peels off clay:
- The type of acrylic paint and clay are incompatible.
- The clay surface was dusty or oily when it was painted.
- The clay wasn’t thoroughly dried when it was painted.
This article addresses three reasons why acrylic paint peels off clay surfaces and how to avoid them when creating your next clay and acrylic masterpiece. So without further delay, let’s dive right in.
Table of Contents
Types of Acrylic Paint
One of the first things to keep in mind when tackling a painting project that involves acrylic paint and clay is to note that not all clays and pigments are created equal. Sometimes they will peel, and others might chip
! Some types of paint work better on some types of clays.
Art Acrylics
When identifying acrylic paints, a good starting point is to look at the type of container the paint is stored in. Metal and plastic tubes (like mini-toothpaste tubes) generally indicate that you are dealing with an art acrylic medium. These tend to be thicker-bodied and have very vibrant colors.
Because they are thicker, they’re great for working in smaller areas but not that great for large coverage areas since they are harder to spread out thinly. Unlike craft acrylic, one coat of artist acrylic is usually enough to cover a surface in color.
Craft Acrylics
Another type of acrylic paint is craft acrylic. This type of acrylic paint generally comes in small bottles with a snap-top lid.
Craft acrylics are thinner bodied and flow much more effortlessly. However, if you’re covering a dark surface with light-colored paint, you might have to apply several coats to cover up the surface color.
Household Paint
Finally, the third type of acrylic paint is household paint. This paint comes in cans of various sizes and is generally purchased from a home improvement store — sometimes even branded as latex paint.
This paint behaves like craft acrylic but usually comes in much larger quantities. If the paint has been sitting for a while, you’ll notice it will start to separate at the top, so stir this type of paint before using it. This paint is best used to cover huge surfaces, such as a wall.
If you are interested in taking an even deeper dive into acrylic paint types, check out this excellent in-depth, informative article on types of acrylic paints by Acrylgiessen.
Types of Clay Surfaces You Might Encounter
When people use the word “clay,” they could mean a wide variety of materials that can be generally molded by hand or machine into a shape. Through drying or firing, some clays result in a hardened final form. Other clays cannot be set and will remain plastic in shape.
There are four main types of clay surfaces.
Terracotta or Other Kiln Fired Clay
This type of clay is most commonly seen in dishes or pots. Fired clay can be glazed or unglazed.
Glazed surfaces such as mugs and plates are not recommended for use with any acrylic paint as the glaze acts as a glass surface, protecting the clay from food, water, and dirt. This same layer of protection also prevents the clay from being painted on. Any acrylic paint will just wash or peel right off.
Unglazed fired clay, however, lends itself well to paint. It doesn’t have a shiny glazed surface to protect it, so all types of acrylic paint will stick right onto it. Great examples of unglazed clay include terracotta flower pots and items known as bisque ware.
Air Dry Clay
This type of clay can look and feel like fired clay with one notable difference; it can’t be glazed, so it is not food safe. But that doesn’t mean that it can’t be used for loads of other decorative items.
When this clay is dry, it takes most acrylic paints nicely. However, be cautious when using craft or household acrylic because water can degrade the fragile air dried surface. Play-Doh can also be considered an air dry clay and can be painted with acrylic paints.
Polymer Clays
Polymer clays are craft clays made from a type of plastic that can be hardened in a regular household oven. Once this polymer clay has been fired in an oven, it can be painted with acrylic paint.
While all kinds of acrylic paint can work on it, polymer clay tends to take artist and craft acrylics best as thinner paints will need a few coats to look vibrant on colored polymer clay. Polymer clay also contains a few plasticizers that can at times repel thinner-bodied acrylic paints.
Plasticine
Plasticine is the name given to clays that do not harden through firing, baking, or air drying. They stay plastic and moldable. This type of clay is not recommended for painting because it contains a large amount of oil that repels paint. Any acrylic paint applied to this surface will flake off or smear off, resulting in a lot of mess.
As you can see, the type of paint and clay matter when painting on a clay surface. Making sure you have the right paint, and a surface that will take paint is key to having a successful project.
It can Bring Issues if the Clay Surface Was Dusty or Oily When It Was Painted
A major reason why acrylic paint peels off clay surfaces is failure to clean the surface before painting. It doesn’t matter whether you are breathing new life into an old piece or making a new clay piece from scratch. This might sound silly – if a piece of clay is dirty, why wouldn’t you clean it first?
The problem is that even a surface that looks perfectly clean might actually contain a small amount of dust or oil. So as a good rule of thumb, always wipe down a surface you’re about to paint with a dust-free, damp cloth.
If your piece is super dirty, you can use a small amount of cleaner to wipe it off. Then, go back and wipe the cleaner off with a damp cloth after ensuring no residue remains. Once you’ve wiped the surface off, give it a few moments to dry completely before painting.
Also if The Clay Wasn’t Thoroughly Dried When It Was Painted – Major bummer
Another pitfall you might encounter when painting a clay surface is failure to set it up correctly before painting. Going back to the different types of clay, that could mean several things.
- Polymer clay. For polymer clay, that means it was baked in an oven at the proper temperature for the right amount of time, as per the accompanying instructions. Polymer clay that hasn’t been baked long enough will be rubbery and somewhat squishy and might contain cracks.
- Air dry clay. One way to tell if air dry clay or fired clay has dried enough is with the cheek check. Simply hold the object to your cheek and if it feels cool, know that it hasn’t dried out enough. Put it in a warm, dry place and keep checking it until it no longer feels cool to the touch.
If the clay hasn’t dried or cured long enough before it is painted, the resulting trapped moisture can rise up through the paint, resulting in long, peeling cracks. If you notice that on a finished piece, know that moisture was probably the culprit.
Final Words
Painting clay with acrylic paints can be rewarding and fun. Additionally, it is a great way to add a personal touch to clay items. Keeping the above tips in mind while you’re painting will help ensure that your piece lasts for many years to come.
Sources
- Acrylgiessen: What Is Acrylic Paint?
- Thesprucecrafts: Common Problems With Acrylic Paints
- Artincontext: What Is Acrylic Paint – Acrylic Paint Uses, Ingredients and More