Most oil painters have heard of the ‘fat-over-lean’ rule, though the explanations behind it might not at all times be totally understood. Working fats over lean – by layering successively fatter, extra versatile layers of oil paint over leaner, much less versatile ones – helps to contribute to the longevity and stability of an oil portray. On this article, I describe the results of not abiding by the approach, with demonstrations for making use of the strategy appropriately each with and with out utilizing medium. Articles within the Methods Collection outline the that means and context of artwork making processes and provides sensible tutorials on the right way to work with them.
Definition: Fats in oil paint describes a excessive oil content material, and lean describes a low oil content material. When it comes to mediums, a ‘fats’ one has a better ratio of oil to solvent than a ‘lean’ medium, which has a better ratio of solvent to grease. The rule ‘fats over lean’ states that lean layers of paint must be utilized first to an oil portray, adopted by successively fatter ones on prime. That is performed by rising the oil content material of every further layer with medium, or by working with successively ‘fatter’ colors. This ensures that oil work could have longevity by means of correct curing by sustaining the pliability of the floor layers of paint, as these under start to dry and grow to be rigid.
The Impact of Fats Over Lean
The results of working fats over lean in oil is a secure portray with sheen and wealthy color that’s outfitted to face the take a look at of time. When every further layer of paint comprises extra oil than the one earlier than, cracking and flaking are prevented for the reason that prime layer is at all times essentially the most versatile. Oil paint dries by means of a course of referred to as oxidation, the place the paint reacts with the air to harden over a very long time. That is in contrast to water-based paints, which dry in a short time by means of evaporation, leaving the pigment behind. As oxidation is going on, the oil paint expands and contracts on the floor. If a lean – faster-drying and fewer versatile – layer is painted on prime of a fats – slow-drying and extra versatile – layer, the fats paint under can proceed to maneuver and pull the brittle lean layer aside, creating cracks.
One other consideration is that fats layers are likely to dry to a shiny end, whereas lean ones seem drier and extra matt. Correctly adhering extra color to fats shiny paint is tougher than lean dry paint – so this rule can also be vital for correct layering and finishing a portray with constant sheen.
The Historical past of Fats Over Lean
The time period ‘fats over lean’ isn’t attributed to a single artist or motion, however is as an alternative a normal rule for oil portray that has been shared amongst artists for generations. By means of observing the historical past of portray and years of examine by paintings conservators, it’s extensively understood to be one of the best follow for secure oil portray. The impact of fats over lean utilized efficiently might be seen in work which are lots of of years outdated and have maintained a secure floor with sheen. These with areas of ‘lean over fats’ usually tend to deteriorate as they age. Though portray lean over fats isn’t the one issue that may have an effect on a portray’s stability – the bottom, high quality of the assist, humidity, pigments, and publicity to gentle can all contribute to how an paintings ages.
Corneille de Lyon
Oil on wooden, 21.3 x 16.5 cm | 8.4 x 6.5 in
The Metropolitan Museum of Artwork
The artists of the Northern Renaissance refined oil portray strategies by growing their works in layers of glazes, to the diploma that Jan van Eyck was as soon as wrongly attributed with inventing the medium. By portray successive layers of oil paint in glazes, he created masterful oil work on wooden which have retained their brilliance to at the present time – over 500 years later.
Jan Van Eyck
Oil on canvas transferred from wooden, 56.5 x 19.7 cm | 22.2 x 7.8 in
The Metropolitan Museum of Artwork
The artists of the Renaissance had been conscious of the fat-over-lean precept – their works sometimes started with a lean underpainting, earlier than being constructed up in fattier layers. We are able to see this within the underpaintings that stay incomplete from the interval, reminiscent of Doge Alvise Mocenigo Introduced to the Redeemer, by Tintoretto, the place the lean sketch of figures by no means to be realised hover within the background, surrounded by the totally rendered figures within the palatial room painted with fatter layers.
Jacopo Tintoretto
Oil on canvas, 97.2 x 198.1 cm | 38.3 x 78 in
The Metropolitan Museum of Artwork
However, work with extra irregular, experimental surfaces are troublesome to preserve, the place the oil content material between layers varies extra spontaneously. This could generally give oil work a mottled sheen, the place some areas of the paint seem ‘drier’ as a result of there may be lean paint utilized to the floor, subsequent to shinier ‘fats’ paint. Sooner or later, the dry, lean areas are prone to crack due to the fats paint beneath them.
Demonstrations of Fats Over Lean
Portray Fats Over Lean With out Medium
Oil paints have particular person oil contents which aren’t at all times detailed on their product descriptions or packaging. The manufacturers I may discover which have printed them on-line are Williamsburg, Michael Harding, and Outdated Holland – although there could also be extra accessible, so it’s price researching the manufacturers that you’ve in your package. Some oil colors are naturally fatter than others, as a result of a better oil content material is required to make the particular pigment they include right into a secure paint. Since some oil paints are oilier than others straight from the tube, an intuitive approach for working fats over lean is to deliberately keep away from making use of a paint that you understand is oily within the first layer of a portray, and reserve it for later.
For my first demonstration, I painted instance colors for a fat-over-lean oil portray with out utilizing any medium, by inserting paints with successively larger oil content material subsequent to one another. I labored with paints from the Michael Harding oil vary on a sheet from a Jackson’s Oil Paper Block. Their chart lists oil by quantity on a scale from very low to excessive, so I’ve chosen paints from every step of the chart.
To use my leanest layer on the left, I used Naples Yellow, which has low oil content material, adopted by Olive Inexperienced within the center, which has common oil content material, after which Everlasting Brown on the fitting, which has excessive oil content material. When layered on prime of one another, these colors would type a secure fat-over-lean portray. I wouldn’t apply Naples Yellow over Everlasting Brown with out including a fats medium, as a result of this is able to imply portray lean over fats.
Portray Fats Over Lean with Medium
If you add medium to a paint, you modify its oil content material. Relying in your most well-liked mixture of solvent and oil, completely different ratios will work higher in your explicit portray course of, so it’s vital to experiment to search out out what fits you finest. So long as the oil ratio will increase with every layer, you don’t essentially have to begin a portray with a really lean layer. In case you’d choose to work thickly or with an oily medium to start with, simply make sure that the oil content material is larger in any subsequent layers, and provides the primary layer sufficient time to dry down to offer it fat-over-lean stability.
As a normal rule, it’s additionally vital to keep away from mixing an excessive amount of medium into oil paints, since it could possibly make them excessively skinny, which ends up in uninteresting colors, a brittle floor, and the potential of sinking into the bottom. When portray fats over lean, it’s pointless to make an excessively lean first layer. As a substitute, the goal is to progressively enhance the proportion of oil because the portray develops.
In case you aren’t positive the place to begin, our articles Watching Paint Dry: Drying Oils and A Information to Oil Portray Mediums are useful for figuring out the qualities of various oils and mediums.
For the aim of this instance, I labored with the traditional mixture of Refined Linseed Oil and Distilled Turpentine. In case you’re a newbie, utilizing the next three ratios and making ready and labelling jars to retailer them in to allow them to be reused will hold you on monitor.
To make the first layer of a portray, measure and blend a medium with a ratio of 1:2 – 1 half linseed oil to 2 elements turpentine, utilizing a small measuring jug. Then permit this layer to dry earlier than shifting to the subsequent layer and medium. This primary layer would be the quickest drying, with the bottom oil content material.
For the second layer, combine a medium with a ratio of 1:1 – 1 half linseed oil to 1 half turpentine. The quantity of oil and solvent is equal on this layer. It is going to take longer than the primary one to the touch dry, because it comprises extra oil.
For the ultimate layer, combine a medium with a ratio of 2:1 – 2 elements linseed oil to 1 half turpentine. That is the oiliest layer, which can take the longest to dry and have the best sheen. So as to add extra layers to this portray sooner or later, make sure that to keep up or enhance this oil ratio to maintain the portray fats over lean.
To reveal the impact every medium has on the looks and dealing with of oil paint, I swatched Michael Harding Forest Inexperienced oil paint with each on a sheet from a Jackson’s Oil Paper Block. As you’ll be able to see, the gloss and physique of every stroke elevated because the medium turned progressively fatter.
When artists achieve confidence in oil portray, they don’t essentially measure out the oil to solvent ratio in medium jars. Many artists will intuitively add oil as they work by noticing the altering sheen and circulation of their paint when blended with medium.
To bypass any fear about mixing mediums, Chelsea Classical Studio created pre-prepared mediums that are labelled Lean and Fats. By portray with each so as, you’ll be able to guarantee your oil work are layered with stability.
Additional Studying
A Information to Oil Portray Mediums
What’s the Finest Non-Poisonous Oil Portray Solvent?
Experimenting with Jackson’s Oil Portray Mediums
Store Artwork Provides at jacksonsart.com
