The 10 Most Common Mistakes Painters Make |
John Cosby, “Aliso Creek Path,” 48 x 64 in.
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The 10 Most Common Mistakes Painters Make
By John Cosby

1. Bad Drawing
In their rush to paint, many people don’t bother with learning to draw well. Drawing time is not only well spent — it becomes an integral part of the planning process and certainly shows in your final painting.

2. Not Creating an Effective Block-In
This is arguably the most important phase of a painting, as the elements are easily arranged and rearranged at this point. Color and tonal decisions are also made best at this phase. Detail should be avoided, as the big picture and the relative massing of the painting is what you are going for. Light and shadow is established in the block-in. If it doesn’t feel right at this stage it rarely will feel right at the end.

3. Not Thinking Through Their Color Key
An idea of both color harmony and intensity is best thought through in advance of executing the painting. The mood of a painting is influenced by color choices. A good painting will have a color harmony that is reliant on either a complementary palette, like red and green or blue and orange, which are direct complements, or move into a triad approach, which splits the difference between the complement and the other color; e.g., orange, green, and violet.

4. Not Making Good Decisions with Gray or Neutral Harmonies
Neutrals are arguably the most interesting colors in a painting and therefore should be well considered. A color becomes a neutral anytime you take a pure color from the outer ring of the color wheel and mix it with a color not adjacent to it. The further you move around the wheel the more neutral it becomes. The most neutral mix is the direct complement across the wheel. Temperatures of these neutrals are easily controlled once you understand how to make them.

5. Compositional Errors
If you want a powerful painting, composition is a subject that is well worth developing some knowledge of. Leading the eye through a painting is the responsibility of the painter. There are many learnable, established compositional forms available to all artists, and so it’s easy to improve your basic knowledge. Once you have a solid understanding the rules can be bent.

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6. Lack of a Defined Area of Interest
What is the painting about? Every painting needs a purpose to be effective. As we are in the predator class of vision and not the prey class, we see by focusing specifically on one area of a scene and the rest fades into the periphery. A creature like a rabbit views the world like prey, and sees detail right to the edge of a scene. Most of our paintings are painted to be viewed by people, so while it seems to impress some viewers to carry details of a scene right to the edges, it is not as emotionally engaging as a powerful, well-defined area of interest that is supported by a less-defined periphery.

7. Consideration of Edges
The edges of a mass or shape tell us a lot about its importance, its spatial proximity, and volume. Attention to certain areas can be drawn or diminished by edge quality. Many painters say there should be one edge that’s sharpest and all others should be softer. As there are many edges contained in a painting this consideration can be a large part of the painting process.

8. Tangential Lines
This is a very common problem I see in paintings. It is a connection of a visual line from one plane or object to another unrelated object or a mass that terminates directly on or against another mass. A good example is the foreground tree that ends exactly against a distant mountain top. When your goal is to create visual clarity, allowing this type of coincidence creates confusion.

9. Not Defining and Maintaining Their Tonal Restrictions
They say “value does all the work and color gets the credit.” Not understanding the importance of limiting your tonal or value range in a painting can seriously disrupt the visual experience for the viewer. Your job is to organize a scene onto a canvas, and a strong tonal idea is the most effective way to do that. Three to four well-defined tones will make a strong visual statement. If you think of color more as an accent, you are more likely to have an effective outcome. An example I use in my classes is the photographer Ansel Adams, whose mastery of a black and white medium gives the viewer all the depth and detail anyone could wish for.

10. Division of Space
A canvas has a definite shape, and the dividing up of this shape is often not as well considered as you might hope it was when it is finished. These divisions are best decided upon in the design phase of the painting. To feature a sky, most of the painting should be sky, and in the case of the land being featured, mostly land. Dividing your canvas into equal spaces of equal importance is a sure way to make a bad painting.

To understand the use of tools like these to make better paintings find a teacher who understands how to pass these concepts to you and practice them with intent and vigor. Your art will improve faster than painting many works without understanding these common errors.

For more painting advice, please visit my website at, and follow me on Facebook and Instagram, learn more about my instructional art workshop Painting Plein Air Impressionism here.

Additional landscape paintings by John Cosby:

The 10 Most Common Mistakes Painters Make |
John Cosby, “Late Light Santa Barbara,” 18 x 24 in.
The 10 Most Common Mistakes Painters Make |
John Cosby, “Aliso Creek Path,” 48 x 64 in.
Painting advice for artists |
John Cosby, “Malibu Canyon,” 30 x 36 in.
Painting advice for artists |
John Cosby, “The Color of Stone,” 24 x 30 in.
Painting advice for artists |
John Cosby, “Colors of California,” 30 x 40 in.

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  1. Beautiful work, John, and sound advice. If you don’t mind, I will print these off and post them in our Painting studio.
    As an art educator, I would condense these 10 into “Do everything you can to learn how to effectively use the Elements and Principles of Design.”


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