Historical Examples of Direct Comparison in Painting

Direct color comparison did not form a single, continuous tradition in the history of painting. However, the same principle appeared repeatedly: artists attempted to place an image, prepared paint, or another color sample directly beside the subject so that both colors could be seen simultaneously.

Not all the methods described below are entirely identical. In some cases, the paint was compared directly with the object. In others, the painting was placed beside the model. In still others, a prepared mixture was checked against an existing painting. But in every case, the artist sought to replace separate observation with a more direct visual comparison.

Leonardo da Vinci. An Image on Glass Beside the Subject
Leonardo proposed securing a transparent sheet of glass and fixing the position of the eye. The artist was then to draw on the glass the tree visible through it, move the glass slightly to one side, and compare the image with the actual tree.
The drawing had to be colored so that it matched the original in form and color, and so that, when viewed with one eye, both appeared to be at the same distance.
This was not yet a comparison of a freshly mixed paint with an object, but it was already a clear example of direct, simultaneous comparison between an image and the subject.
Source: Leonardo da Vinci. Treatise on Painting.



Marshall Smith. Paint on the Tip of a Knife and the Color of the Subject
In his 1692 treatise The Art of Painting, Marshall Smith advised mixing flesh tones and comparing “the color on the tip of the knife” with the hues of the face until the required color was obtained.
The position of the knife relative to the model was not described in detail, but the prepared paint was clearly used as a separate color sample to be checked against the live subject.
Source: Marshall Smith. The Art of Painting, 1692, Ch. XXVIII, p. 77



Joshua Reynolds. The Model and Painting Side by Side
Joshua Reynolds’s pupil James Northcote recorded his advice: work from the greatest possible distance and place the painting beside the model or slightly below it so that the sitter and the image could be seen together.
Here, the comparison was made not with a prepared mixture, but with the image already painted. The principle, however, was the same: the model and the painting were placed within a single field of view and perceived simultaneously.
Source: James Northcote. The Life of Sir Joshua Reynolds, Vol. II, 1819, p. 58



John Singleton Copley. Matching Hues with a Palette Knife
Charles Robert Leslie recorded Benjamin West’s account of John Singleton Copley’s working method. Before touching the canvas, Copley used a palette knife to match a separate hue for every part of the face, including light, shadow, and reflected light.
The prepared hues were matched in advance to individual areas of the subject before being applied to the canvas.
Source: C. R. Leslie. Testimony based on Benjamin West’s account of John Singleton Copley’s technique



John Ruskin. Paint Beside an Aperture
In his 1857 book The Elements of Drawing, John Ruskin advised making an aperture the size of a large pea in a piece of white cardboard and viewing a small area of the landscape through it. Directly beside the aperture, paint was to be mixed with white until it matched the visible fragment of the subject.
The card isolated a small area of the landscape from the surrounding colors, while the prepared paint and the subject appeared side by side.
Ruskin specifically warned that the card had to be turned toward the light correctly. If its surface was insufficiently illuminated, the comparison would produce an incorrect result. This is one of the earliest examples in which direct color comparison was combined with an attempt to control the illumination of the sample.
Source: John Ruskin. The Elements of Drawing, pp. 164–165



Edward Poynter. Direct Comparison in an Art School
From 1875 to 1881, Edward Poynter directed the National Art Training School in South Kensington. The instructions he prepared for the school were later reproduced by John Collier.
The student was required to mix a hue with a palette knife and compare the paint on the knife directly with a plaster cast. The palette knife was held between the eye and the cast, in full light, but positioned so that no glare appeared on the paint.
The situation in which the artist stood near a window while the arrangement was placed in a darker part of the room was considered separately. In this case, the student was instructed to move closer to the cast. Otherwise, the prepared paint would be too dark.
Source: John Collier. A Manual of Oil Painting, 2nd ed., 1887, printed p. 52, PDF file p. 57



John Collier. Direct Comparison of the Palette Knife with the Object
In A Manual of Oil Painting, published in 1886, John Collier described his version of direct comparison.
First, the artist approximately mixed the paint for a particular patch on the object. The artist then raised the palette knife in front of that patch and directly compared the two colors. The mixture was adjusted until the end of the palette knife became almost indistinguishable against the object.
Once a match had been achieved, the paint was transferred to the corresponding area of the canvas. In this way, the large patches of light, shadow, and color were matched one after another until the image began to resemble a mosaic.
Collier warned that the visible color of wet paint changes when the palette knife is turned relative to the light. The canvas had to be placed in sufficiently strong light, but without glare. During checking, the palette knife had to be held beside the painting, parallel to its surface. Only then would the paint look approximately the same after application as it had during comparison.
Collier used this technique as a means of establishing an accurate color foundation, which then had to be refined with consideration for the surroundings and the overall effect of the painting. He also recommended this method to beginners: “It is a very tiring operation, but it should be pursued persistently, since there is no other method by which a beginner could hope to achieve even a reasonably accurate reproduction of the hues of a natural object.”
Source: John Collier. A Manual of Oil Painting, 2nd ed., 1887, printed pp. 16–18 and p. 56



Pavel Chistyakov. Experiments with Color and Tone
Pavel Chistyakov insisted that students should not transfer prepared paint to the canvas without checking it once more:
“Mix the paint, but do not apply it to the drawing without looking at the subject once more.”
Another note says:
“Compare the colors with the subject after placing them on the canvas; and even earlier, when mixing them on the palette, look at the subject and compare.”
There is no documentary evidence here that the paint was held directly beside the object. This was not a direct physical comparison, but a continuous checking of color when moving from the subject to the palette and canvas.
Source: P. P. Chistyakov’s draft notes. Manuscripts Department of the Russian Museum, electronic publication: first passage; second passage



Ilya Repin. Checking Prepared Paint Before a Brushstroke
Nikolai Sychev recalled how Repin corrected a copy of his portrait of Nicholas II. Repin spent a long time comparing the copy with the original and mixing the paint. The brush loaded with paint was alternately brought closer to the canvas at arm’s length and then drawn back again. Only after several checks did the artist find the necessary tone and apply the brushstroke.
Here, the prepared paint was compared not with a live subject, but with an existing painting. Nevertheless, Repin checked the intended brushstroke before applying it, comparing the mixture with the color environment of the painting.
Source: N. P. Sychev. “Memories of I. E. Repin”



Arkhip Kuindzhi. Working Between Palette and Canvas
Mikhail Nevedomsky, describing Kuindzhi’s work with his students, wrote that the artist spent a long time mixing paint on the palette, loaded it onto his brush, and then, extending his arm, once again “checked” the prepared tone against the colors of the painting that the new brushstroke was meant to complement.
Only after this check did Kuindzhi apply the paint quickly and decisively. In this case, what was being checked was not the absolute match between the mixture and a separate sample, but its compatibility with the painting’s existing color structure.
Source: M. P. Nevedomsky. Arkhip Ivanovich Kuindzhi



John Singer Sargent. The Model and Painting in the Same Field of View
Sargent placed his easel directly beside the model and stepped back to his working position. According to Julie Heyneman, from there he saw the painting and the original in the same light, at the same distance, and from the same angle of view.
William Rothenstein likewise recalled that, when working life-size, Sargent placed the canvas level with the model and stepped back until the sitter and the image appeared equal before his eye.
Sargent did not hold the prepared mixture beside the model. He compared the color area already painted on the canvas with the subject. Nevertheless, this was a full simultaneous comparison of the painting and the subject.
Source: John Sargent, 1927, printed p. 182, PDF file page 280



Nikolai Krymov. Direct Comparison and Experiments with Tone
Krymov recounted how, in his youth, he copied a small landscape by Narcisse Diaz de la Peña in a museum. He could not find the color of the patch of sky between the trees.
The artist waited until the attendant had left the room, mixed the paint, and touched a section of the painting with his brush. It turned out that the sky, which appeared blue, had been painted with raw umber and white. To check the light areas in paintings, Krymov placed a sheet of white paper against them and later recommended conducting the same experiment at the Tretyakov Gallery.
Compared with the paper, white objects in paintings proved considerably darker, although they continued to be perceived as white. Seeking a constant reference for determining the overall tone, Krymov used the flame of a burning match. The artist held it at eye level and compared it with the evening sky, a white wall illuminated by the sun, and other areas of the subject.
He then repainted three studies of the same motif under sunny, overcast, and evening light, each time coordinating the overall tone with this external sample. Thus, Krymov consistently employed physical samples and controlled setups while investigating how perceived color depends on light intensity, illumination, and the surrounding context.
Sources: N. P. Krymov’s account as related by F. S. Bogorodsky; Krymov. The Experiment with White Paper; N. P. Krymov. “On Painting”; the experiment with a match and the evening sky; comparison with a sunlit wall and the repetition of the three studies



Contemporary Forms of Direct Comparison


James Gurney. Color Isolator
James Gurney proposes a card, one half of which is painted white and the other black. Through holes in the card, a small area of the subject can be isolated, and a stroke of prepared paint can be placed beside the hole.
Gurney points out two limitations. The brightness of the subject may exceed the capabilities of paint. In addition, the visible lightness of the card itself changes depending on its position relative to the light. Therefore, for the comparison to be useful, the card must be held at a properly chosen angle.
Source: James Gurney. “Color Isolator,” 2010



Mark Carder. “Color Checker”
Mark Carder, the author of the Draw Mix Paint system, applies prepared paint to the original “Color Checker” and holds it in front of the still life. Carder emphasizes that, before beginning this kind of checking, the lighting of the setup and the workspace must be matched.
When working from a laminated photograph, he applies test brushstrokes directly to the photograph.
Sources: Mark Carder. Step 6: Beginning to Mix Colors; https://youtu.be/TuZ0t5FR9f0?si=L5n1z09T0jWAlPop



Paul Foxton. Checking Prepared Paint Through a Color Isolator
Paul Foxton uses a card with a hole to isolate a small area of the subject. To check a prepared mixture, he applies the paint to a separate card and holds the sample beside the hole.
Foxton specifically warns that the sample must be held parallel to the surface of the painting, at the same angle to the light. Otherwise, the color will be perceived incorrectly.
Source: Paul Foxton. The Chroma Curve: How to Paint Light and Shadow, 2018



René Milone. Paint on a Palette Knife Directly in Front of the Model
René Milone proposes mixing paint on the palette, taking a small amount of the mixture on the tip of a palette knife, and comparing it directly in front of the model. The mixture is adjusted until the paint visually merges with the observed color of the subject.
Milone warns, however, that literally reproducing all the colors found in this way can make a painting disjointed and that it often requires subsequent harmonization.
Source: René Milone. Le choix des couleurs en peinture, 2025



Patrick Okrasinski. Paint on a Palette Knife in Front of the Subject
Contemporary plein-air painter Patrick Okrasinski uses a palette knife not only to mix paint but also as a portable color sample. He raises the prepared mixture in front of the area of the landscape he intends to paint and compares them directly.
Okrasinski specifically emphasizes that the palette and painting must be under the same lighting. In his workshop materials, this technique is shown literally: paint on a palette knife is compared with the sky or another area of the subject.
Source: Patrick Okrasinski. 3 Tips for Color Matching Outside