15 Proven Ways to Create the Illusion of Depth in Art
Updated: 10 Aug 2020

Intro
In art, when drawing in a realistic style, it is important to draw from direct observation or by using reference images.
However, for an initial sketch or when drawing from imagination, there are several proven methods to create the illusion of depth.
1. Volume
Unlike flat objects, 3D objects appear to have volume and therefore indicate depth in the painting.
A three-dimensional object will have highlight and shadow areas depending on where the light source is located.

Example:

2. Size
According to the rules of perspective, the farther an object is, the smaller it will look.
For that reason, when drawing similar objects in different sizes, one can conclude that smaller objects are farther away, thus create a sense of depth in the painting.

Example:

Size can also be used to create a sense of space.
Adding small objects to a defined space will make it look big:

Adding big objects to the same space will make it look small:

3. Overlap
A body concealing part of another body indicates that the body it is hiding is farther away.

Example:

If you like my tree drawings, feel free to visit my guide on how to draw any tree with a pen.
4. Position/Height
Objects that their base is positioned higher on the painting surface will look farther away.

Topography conditions, such as mountains, hills or valleys, are important in object placement.
In most cases, the base of closer objects will be lower on the drawing surface AND the top part of close objects will be higher than far objects.

The reason is the observer's visual angle, meaning not measuring in meters but in degrees, in perspective.

Example:

When looking from above, the top part of closer objects will be lower on the painting surface.

5. Contrast & Details
The contrast between the dark and light areas decreases, as does the amount of details, as an object is farther away.

That is to say, when drawing or painting, areas with high contrast will come forward and areas with less contrast will recede.
Example:

6. Edges
When an object or surface ends in a sharp way, it means it has a hard edge.
Soft edges are when objects end in a gradual way, from dark to light.

Foreground objects will have hard edges and therefore in focus.
Background objects will have soft edges and therefore blurry.

7. Horizon
Dividing the painting into ground and sky by a horizon line, mountain range, vegetation or any other way, attests to depth.
In addition, by adding ground to the painting, the objects stop "hovering".

Pencil drawing example:

For a list of equipment I use for drawing, visit my guide for pencil drawing supplies.
8. Perspective
By using linear perspective, it is possible to demonstrate depth in a realistic manner.

Example:

9. Foreshortening
Objects in front of the viewer, such as buildings, trees, mountains, people, etc., will look smaller as they are farther away, but will maintain the ratio between height and width in the painting. This means that there will be no distortion.
On the other hand, when we change the object (or our) angle of sight, and the object is now along the line of sight, it will get shorter in that direction.

This distortion is due to the angle of sight. The more an object is in our direction of sight, the more it will be distorted (becomes much shorter in that direction).
For example, a lake that in reality can be round, in perspective becomes more elliptical as the distance between it and the observer grows.

Note: Cast shadows will be subject to foreshortening (unless they are in front of us).
Example:

For recommended drawing pens, visit my technical pens review for artists.
10. Colors
According to the rules of atmospheric perspective, the farther an object is, the more its color (hue) shift towards the background color which is usually blue sky.

11. Saturation
The farther an object is, the less saturated its color will be.
In other words, its color will be less rich, bright or intense, therefore becoming dull or neutral.

Example:

12. Temperature
Purple, blue and green are cool colors; they bring to mind the ocean.
Red, orange and yellow are warm colors; they bring to mind fire.
The farther away an object is, the more atmosphere particles will be between it and the observer, i.e. the atmosphere color will have a bigger effect.
When the sky is blue, the color of background objects will shift gradually toward a blue hue due to scattered light and therefore become cooler.
Foreground objects will be warmer than the background objects since there are less atmosphere particles between the observer and the foreground objects.
Opposite phenomenon may occur in sunrise or sunset.

Done with marker pens for artists.
13. Values
According to atmospheric perspective, farther objects will have higher brightness values, meaning their color will be lighter.

For monochromatic drawing, like pencil drawing, the same principle applies.
The key is to press harder with a drawing pencil for darker values or to use pencils with different brightness values.

In addition, transitions (gradient) in brightness values can be used to create the illusion to depth.


14. Cast Shadow
It is important to paint or draw cast shadows when necessary and adjust their direction to the opposite side of the light source.

Example:

In order to learn how to compose a scene and render it, read my tutorial on composition drawing.
15. Brushstrokes & Marks
Some painting styles are done with a collection of single brushstrokes. For example, painting grass blades or leaves.
In these cases, larger paintbrushes can be used for foreground strokes.
The same can be done with a technical pen. Using a pen with bigger nib size for bigger marks when drawing foreground objects and smaller nib size for background objects.

Example:

For an initial sketch, the direction of lines/marks or brushstrokes is important.
Same basic shape with different marks direction tells a different story:

When planning a painting, marks direction play a major role:

And they are necessary when painting.
Example:

If you are new to oil painting, it is good to know the different types of paintbrushes for oil painting.
Summary
The key to create depth when painting (or drawing) is the use of different methods to produce a three-dimensional look on a two-dimensional surface.
Simply put, there is no actual depth in painting but an illusion of depth.
When you draw or paint from observation, the knowledge of what to look for will improve your art and, when drawing or painting from imagination you can use your artistic license with these methods.
Colors:
While using colors, it is important to pay attention to color attributes such as hue, saturation, value and temperature.
In a monochromatic drawing, correct brightness values are crucial.
Landscape vs still life:
For landscape painting, it is important to understand linear and atmospheric perspective.
When painting a still life, methods like contrast, overlap, edges and so on will be used to create depth.
Note:
One way to practice with quick results is using a mechanical pencil for sketching.
Additional Resources:
After understanding depth, it is time for The 8 Key Factors for Painting Realism.
For realistic pen & pencil drawing: Beginners Guide: Realistic Pencil Drawing.
If you like drawing with pens, you might like my flower drawing guide.