type of paint

The Science Behind Paint

Read Time: 4 minutes

Look around your room or the area where you are sitting — chances are, you are looking at paint in one of its many forms. Whether it’s decorating your walls, your desk or a painting hanging in a frame, there are an enormous variety of applications for this common decorative material. Have you ever wondered what it takes to make paint? We’ve taken an in-depth look into the science behind paint!

Four Ingredients in Every Type of Paint Paint

Whether you’re breaking out a set of acrylic paints to create a masterpiece, or popping open a can of wall paint to redecorate your house, there are four ingredients that make up every type of paint:

  • Pigments
  • Binders
  • Solvents
  • Additives

What do these items do, and what roles do they play in the creation of bright and colorful paint?

Pigments

Pigments are the basis for the color in every paint — the higher the pigment quality, the more color the paint can produce. High-quality paints have more pigment in them as well, enabling you to get the color you’re going for without having to add a bunch of extra coats to the wall.

Paint pigments can be made from just about anything, both natural and artificial. White is usually made of titanium dioxide, while reds and browns often use naturally occurring things like iron oxide, or rust. Chromium oxide makes green, and black is usually made from carbon or charcoal.

Binders

Binders are the glue that helps the pigments stick to the surface you’re trying to paint. Traditionally, paint binders were made with natural oils like linseed oil, but as technology and chemistry progressed, paint manufacturers began replacing this natural binder with things like synthetic plastics and rubbers.

The binder also creates a layer of protection that keeps the paint from flaking and peeling off when it’s exposed to the air and other environmental factors.

Now you have the first two components to make paint, so it’s time to start mixing. Unfortunately, when you mix these together, you get a thick, goopy substance that doesn’t spread well when you put it on a brush. That is where solvents come in.

Solvents

Solvents are the third component in paint mixing. These components act as a thinner to make the pigment-binder mixture easier to spread. Many paints, such as watercolor, use good old H20 as their solvent. Water-based paint is easier to wash out of things like clothing if you make a mess while you’re painting.

Longer-lasting paints require a stronger solvent. Some use organic components like naphtha, a byproduct of petroleum — this substance is most common in oil paints, which makes it harder to clean up these paints.

It’s extremely important to mix your paints before you use them. Paints that use naphtha-based solvents, for example, often separate during storage, leaving the solvent as a clear layer on the top of the pigment-binder mixture.

Additives

Once you’ve got the first three components together, it’s time to add some additives depending on the type of paint you need. This will vary from substance to substance, but can include:

  • Ceramics to make the paint more durable
  • Glitter or fluorescent materials to make the paint shimmer, glow in the dark or react to black light
  • Mildewcides that prevent mold and mildew growth once the paint has been applied

These elements aren’t necessary to the creation of a functioning paint, but they can make the paint last longer and even make it a little more fun, which is great for artistic applications or kids rooms.

How to Make Your Own Paint

Now that you know the basics of paint-making, it’s time to move on to the next step — making your own! This is a great activity to keep the kids occupied on a rainy day.

You can paint with just about anything. Coffee or tea makes attractive brown paint, which will dry well and not attract bugs as long as you don’t add any sugar or milk to them. You can even mix your own paint from items you find in the kitchen.

Mix your own watercolors with baking soda, vinegar, corn syrup and cornstarch. These four items together become your binder. Add food coloring for your pigment and allow the paints to dry in ice cube trays or muffin tins. Water becomes your solvent, and you have everything you need to make basic paints.

Experiment with DIY paints and see what you can come up with! Now you know the essentials, the opportunities are endless.

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Category: Chemistry

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Article by: Megan Ray Nichols

Megan Ray Nichols is a freelance science writer and science enthusiast. Her favorite subjects include astronomy and the environment. Megan is also a regular contributor to The Naked Scientists, Thomas Insights, and Real Clear Science. When she isn't writing, Megan loves watching movies, hiking, and stargazing.