The demi-pâte française
N.B. To my knowledge, there is no English translation of the term “demi-pâte” (demi=half and pâte=paste). The books dealing with this technique are of French origin and have never, to my knowledge, been translated into English. This could partly explain why few English-speaking painters are familiar with this technique, although they have great admiration for Bouguereau’s exceptional rendering. For example, the precious work of Xavier de Langlais “La technique de la peinture à l’huile” (The technique of oil painting), thanks to which I was able to direct my research in the right direction, is only published in French.
As its name suggests, the demi-pâte technique was practiced mainly by academic painters in the 19th century in France. William A. Bouguereau is the most famous representative. It was he and other masters of the same ilk such as Cabanel, Gérôme, Meissonnier and many other exceptional artists of that time who brought this technique to its maximum level of beauty and effectiveness.
ASPECT
As you can imagine, a work made in demi-pâte does not include impasto. The material is dense, smooth in appearance, lustrous and translucent. The colors are passed with delicacy – according to the degree of mastery of the performer.
USE – MALLEABILITY
The exceptional rendering of the works of the masters is closely linked to the use of resins. A resinous painting medium gives us a dense and malleable paste under the brush. This plasticity of the material is gradually accentuated during execution and the painter synchronizes his work so as to take maximum advantage of this progressive grip. Thus, he can refine his rendering throughout his day. He repeats everything by layering several times until he can create the most subtle Wet-in-Wet glazes at the end of the day.
It is enough to use a resinous medium once to understand that all the pleasure of painting depends on it.
WHO IS THE DEMI-PÂTE TECHNIQUE FOR?
Painting in demi-pâte requires following a very rigorous execution protocol. So rigorous that it is essential to have reached a very high level of mastery to be able to rub shoulders with it.
The slightest hesitation during work will cause us to lose the momentum of progressive setting of the paste. Here, the hesitations, the incessant back and forth (doing, undoing, doing, undoing) are disastrous. Each brushstroke should be a step forward.
Therefore, even before starting to paint, it is essential to clearly visualize all the steps to follow until the final result, which means spending a lot of time in preparatory studies.
It may seem paradoxical, but the more rigorous the preparatory work, the more the rendering will be spontaneous because the mind is then freed of all preoccupations. Only the pleasure of painting remains.
Risk of embus (matte or dull surface)
The main constraint of the demi-pâte is having to respect long drying times (two weeks on average) between rework. The work done in one day can in no case be retouched the next day, otherwise it will cause very unpleasant embus.
If you are one of those people who can’t help but keep coming back day after day to their board in an intuitive and disorderly way, this technique is not for you.
CHEMISTRY AND PHYSICS OF MATERIALS
To practice the demi-pâte, it is essential to fully understand the behavior of the material and to do this it is necessary to have a maximum knowledge of the trade.
In fact, any painter worthy of the name and having professional pretensions must have a minimum knowledge of the properties of the products he uses. And this regardless of the pictorial genre he practice.
An introductory course in this knowledge is presented at the Académie des beaux-arts de Québec: THE SECRETS OF OIL PAINTING: MATERIALS AND THEIR GOOD USE This course is available on video accompanied by a written document (in french only)
To order the video: http://www.acbaqc.com/fr/video
You can watch the trailer on Youtube: https://www.youtube.com/@academiedesbeaux-artsdeque5530
Content:
Supports: Wood, canvas and other mounted supports
Coatings: Organic gesso with protein glue, acrylic gesso
Pigments: Stable pigments vs pigments to avoid, how to read a tube of Paint
Oils: Properties, siccativeness. Clarity and yellowing, Durability
Resins: Function. Vegetal or synthetic resins, hard and tender, balms
Solvents: Vegetal solvents: D-limonene, rectified turpentine, essence of aspic
Petroleum-based mineral solvents, odorless solvents
Varnishes: Varnishes for painting and retouching. Temporary and final varnish
Their composition, function and when to apply them.
PAINTING MEDIUM by Bouguereau
It is presumed today that Bouguereau used mediums based on copal resin: Flemish Siccative Medium and Medium of Harlem Duroziez manufactured by Lefranc & Bourgeois, a house founded in Paris in 1720 and still active.

I painted for several years with these mediums. Copal is a very hard resin which gives the paint layer a very beautiful enamel appearance and gives the paste an unparalleled hardness thereby ensuring a very good durability to the work.
N.B. Contrary to all expectations, the dark color of the copal medium does not affect the brightness of the colors.
Unfortunately, the manufacturer (Lefranc & Bourgeois) recently stopped manufacturing this painting medium, which the company had been producing for at least two centuries. Pernicious effect of supply and demand.
Used properly, it was a very effective but rather capricious medium. The progressive setting of the paste was done by stages spread over a period of about 8 hours. At the end of the session, the paste tended to cure quickly so that you could, for lack of experience, be surprised and not have finished the piece before the paste became too tacky.
HOME MADE PAINTING MEDIUM
Today, I paint with homemade mediums since there is no medium on the market that meets my expectations. It was friends and collaborators with the necessary skills in chemistry who developed the mediums that I use today. By dint of research and experimentation, we have succeeded n perfecting mediums which are perfectly suited to the demi-pâte and which advantageously replace the Flemish siccative medium. The setting is more regular and the execution time is extended. This relieves the execution of great stress.
It is possible that this medium will find itself on the market eventually if demand arises.
Contemporary chemistry has the means and knowledge that can greatly improve the quality of the materials available to painters of the past. Both in terms of mediums and colors (see next chapter: COLORS). For example, I mainly use D-limonene as a diluent.
COLORS
I only use extra fine colors whose durability is flawless. Some have been used by painters for a very long time, others, resulting from contemporary chemistry, have advantageously replaced colors that were too fragile in the past. For example, colors of vegetal origin (Rubia tinctorium) such as Garance NR9 (Madder Lake, Carmin, Alizarin Crimson PR83 etc.) are very beautiful magenta reds but extremely light sensitive. They are fortunately substitutable nowadays by very strong synthetic organic pigments such as quinacridones PR122.
TO CHECK THE SOLIDITY OF YOUR COLORS
It is very important to read labels carefully. All the subtleties and codes to know are very well presented on: https://annemarieboisvert.com/comment-lire-une-etiquette/
In no case can we trust the poetic name attributed to the colors. All manufacturers of oil colors must indicate on their tube the composition of their colors according to an international code. Take note of this code and go to the data sheet at: http://artiscreation.com

For information, here is the list of my favorite colors. My preference for Old Holland is certain, but I also use products from other manufacturers who make quality extra-fine colours.
OLD HOLLAND EXTRA FINE COLORS:
• TITANIUM WHITE (PW6)
Cremnitz White : LEAD CARBONATE (PW1)
• SHEVENINGEN YELLOW LIGHT: MONOAZO (PY74)
• MARS YELLOW: iron oxide (PY42)
• CORAL ORANGE: PYROZOLO QUINAZOLONE (PO67)
• DARK SHEVENINGEN RED: CONDENSED AZOIC (PR214)
• Venetian Red: IRON OXIDE (PR101)
• MAGENTA : QUINACRIDONE (PR122)
• Caput Mortuum Violet (Mars): IRON OXIDE (PR101)
• Carribean Blue: PHTALOCYANINE (PB16)
• Old Delft Blue: INDANTHRONE (PB60)
• Chromium Oxide Green (PG17)
Coming:
MODUS OPERANDI – Process and application of the demi-pâte technique
STEPS :
Preparatory studies :
Research, drawings, composition, color range, cardboard for transfer.
Alla prima execution
Two-layer painting
First layer: examples of Bouguereau at end of life.
Drying time to respect – risk of embus.
Second and last layer
Optional glazes