How to Make Realistic Cast and Form Shadows

cast and form shadows

James Gurney’s, “Poet’s Walk” shows the artist's mastery with light and shadow.

Our world is made up of light and shadow. So all artists need to understand how to create realistic shadows.

Without correct shadow and light relationships, a painting will fall flat. Shadows explain form, depth, and much more. Here at Evolve, we simplify shadows at first, breaking them down into the two categories of cast and form.

When light strikes an object it creates a fairly predictable shadow, depending on the shape of that object. Learning how to identify the way objects affect light teaches students how to make realistic shadows.

So let’s take a look at the two main types of shadows, learning what causes them, how to use them, and how to make them believable in our paintings


Form shadows, like the right side on this sphere, are a soft fade from light into shadow and caused by the shape of an object, in this case, the sphere.

Form Shadows

Shadows can be divided into two broad categories, the first being form shadows.

Form shadows happen when part of an object lies on the opposite side or away from the light source, and therefore does not sit directly in the light. It still is affected by the light indirectly, and has color and dimension, but does not sit in the direct path of the light source.

Form shadows receive this name because they define the form and shape of an object. As the light hits a certain object like a sphere, it dissipates around the sphere, unable to reach certain parts of the object due to its rounded shape.

Because of this gradual fade into shadow, a form shadow has a softer, graded edge when compared to a cast shadow.

These shadows appear very soft and gradual and help to explain the third dimension to a drawing or painting. When painting shadows like this, Evolve students use a gradient technique with the paint to get a soft fade from light into shadow.

When done correctly, the viewer cannot point out where exactly the light changes into shadow but can see a distinct difference between the two.

Understanding how form shadows are created is an important concept for students to understand. As they advance, this skill will help them to create form and dimension in their work.

In this painting by Evolve student Sindy C., you can see a cast shadow on the blue pot, created by the purple cone blocking the light. Can you find the other cast shadow and the form shadows in this piece?

Cast Shadows

Cast and form shadows require different painting techniques. In general, cast shadows have sharp edges and explain that a light is being blocked to create a shadow.

Whereas a form shadow exists because of a light reaching around an object due to form, the cast shadow happens when an object sharply blocks the light source.

For example, in the image above, the purple cone blocks the light completely from hitting the vase in a certain area. This shadow has sharp edges all around, completely blocked by the cone from being hit by the light.

Often, cast shadows have darker values than form shadows, depending on the object they are cast on. Because the light source becomes completely blocked, there is usually less or darker reflected light in a cast shadow.

Painting shadows requires thought about the light source, and cast shadows are no exception. The further a cast shadow falls from the object creating it, the lighter the shadow gets and the softer the edge often becomes.

Knowing this will help you as you seek to make realistic paintings.

In this Evolve painting, you can see that while the light is the focal point, the colorful cast, and form shadows create beautiful dimension in this piece.

Color and Value in Shadows

So now that we have explored two basic types of shadows, how can we make them seem convincing and realistic? For beginners, the first step is to ensure that you use the correct edges for your shadows.

This means that your form shadows have soft edges and the edges of your cast shadows remain razor-sharp.

Once those edges are correct, you can begin to consider the value of your shadows. Value is a critical part of any painting. If your cast and form shadows appear lighter than your objects that are in the light, they won’t function as convincing shadows.

However, the inverse is also a pitfall. Many beginner painters will paint all of their shadows pure black.

However, shadows are not one flat color and certainly not completely black! Instead, they have light and dark values, and color within the shadow.

If you look around in nature, you would be hard-pressed to find a purely black shadow. In reality, various light sources flood into shadows indirectly, bouncing off of other objects and affecting the shadow.

A blue sky, white clouds, a bright yellow field, and various other things will all affect the color of a cast shadow.

Shadows are rarely black, instead, they are affected by the object they cast onto or the environment around them. In order to paint realistic shadows, an artist must keep this in mind and paint shadows with the color they can see in them.

A beautifully accurate and effective example of cast and form shadows, with values carefully considered, by Evolve student May.


Realistic cast and form shadows require stronger concentration than many beginners realize. However, if you start slowly and follow these few rules, you will be off to a strong start in creating accurate shadows.

You can practice today by identifying cast and form shadows in the objects around you and looking closely to see the true value or color of each one. I think you’ll find it a good way to practice and perhaps you will begin to see shadows in a new way.

Click here to learn more about making realistic art!

The 4 Part Framework to Develop Artistic Excellence in 12 Months

Take the FREE Evolve Masterclass

Register to learn the 4 Part Framework taught at Evolve to develop professional level art skills in just 12 months.