Guide to Understanding Watercolor Paint Properties

To See Or Not to See: A guide to understanding the differences between transparent, opaque, permanent, and non-staining watercolor paints.

The beauty of painting is that no matter how long you’ve been at it, there will always be more to learn: new mediums, new techniques, and surfaces.

As you begin to make creative decisions to develop your personal style, you will naturally lean towards the look of certain types of paint or be drawn to the effects they make. Knowing about different properties of paint will help you get there, and so I’ve put together this guide to understanding the differences between transparent, opaque, permanent, and non-staining watercolor paints.

How can you tell if a paint is transparent or opaque?

Comparison of transparent watercolor and opaque watercolor

Transparent and Opaque paints have different applications. For creating thin layers or washes that allow the underlying surface to remain visible, transparent paints are the way to go. Opaque paints, when used without dilution, create solid layers of color that completely cover up anything underneath them.

To determine if a paint is transparent or opaque, try this simple test:

Using a swatch of watercolor paper, draw a solid stripe using a black sharpie. Using the paint in question, paint a few lines over the stripe, not covering it up completely, and allow the swatch to dry (I use a heat gun to speed up the drying process, but you can use a hair drier or a sunny windowsill). Have a look at the result: it should become pretty clear (or not clear) if the paint is transparent or opaque!

What is the difference between permanent and non-staining paint?

Comparison of permanent (staining) watercolor and non-staining

This question comes up very often, and particularly with watercolor painting, knowing the answer will save you much confusion and heartache.

Permanent watercolors, also known as “staining” watercolors, are paints which absorb into the fibers of your watercolor paper, and do not lift off once dry.

Non-staining, or non-permanent watercolors, are pigments which can be applied to the surface of the watercolor paper, and will remain workable - meaning that the paint itself becomes reactivated and can be moved around with water, even after it dries on the paper.

To determine if a paint is permanent or non-staining, try this:

Using a swatch of watercolor paper, apply the paint in question and allow it to dry completely overnight (cue the hairdryer, or my fav, the heat gun). Make sure the paper gets bone dry, all the way through. Now, using a clean paintbrush with a generous amount of water, wet the paper, brushing the surface as you would if you were trying to remove the paint. If the paint does not budge, it’s considered permanent, or staining. If the paint begins to dissolve, you have a non-staining paint on your hands. Literally.

Note: you can also discover this the hard way when you get this kind of watercolor on your clothes and it doesn’t come out.