The fat over lean rule in oil painting is a principle that ensures the long-term stability of the paint layers. This rule states that each successive paint layer should contain more oil than the one beneath, creating a flexible upper layer that prevents cracking as the painting dries and ages. However, the “fatness” or “leanness” of a paint mixture is more accurately determined by the overall oil-to-pigment ratio relative to the critical pigment volume concentration (cPVC) than by the inherent properties of the medium itself.
How Fat Over Lean Relates to Critical Pigment Volume Concentration
The concepts of fat over lean and critical pigment volume concentration (cPVC) are closely linked because both principles address the balance of oil and pigment, which determines the paint’s structural integrity. While the fat-over-lean rule guides the layering of paint to ensure flexibility as layers dry, cPVC defines the optimal binder-to-pigment ratio within each layer. When paint is formulated near its cPVC, typical of most artists’ oil paint, it has just enough binder to hold the pigments together without excess oil, maintaining the right degree of flexibility and minimizing risks like cracking and yellowing. By understanding both concepts, artists can make informed decisions about paint mixtures and medium use, ensuring that each layer adheres to the fat-over-lean rule and maintains structural stability. Integrating these two principles enhances the painting’s longevity and visual quality, reinforcing a cohesive approach to oil painting techniques.
Understanding Pigment Volume Concentration (PVC) and Critical Pigment Volume Concentration (cPVC)
Pigment Volume Concentration (PVC) is the ratio of pigment to the total volume of solids in the paint. For example, a PVC of 30% means that 30% of the total solids in the paint are pigments, while 70% are binder solids (e.g., oil, resin).
Critical Pigment Volume Concentration (cPVC) is the point at which there is just enough binder to wet the pigments without leaving excess oil in the paint film. Paint near or at the cPVC is flexible, semi-glossy, and less prone to cracking or sinking in, as well as yellowing. It is at this balance point that paint achieves optimal structural stability.
Fat Over Lean: Paste Mediums vs. Oil Painting Mediums
To achieve proficiency in oil painting, artists must not only understand the fat-over-lean rule but also the characteristics of the mediums they use. Oil painting mediums can be broadly divided into two categories: paste mediums, which contain extender pigments, and oil painting mediums, which are primarily composed of oil and resin without extender pigments. Each type of medium interacts differently with the paint, influencing the oil-to-pigment ratio and the paint’s critical pigment volume concentration (cPVC). By understanding these distinctions, artists can choose the appropriate medium to achieve desired effects while adhering to the fat-over-lean principle. The following sections will explore how these mediums impact paint formulation and how their use affects the stability and flexibility of oil paintings.
Paste Oil Painting Mediums:
- Paste mediums contain extender pigments (pigmentary solids), binder solids (oil and resin), and possibly solvents (non-volatiles).
- Extender pigments in paste mediums do not significantly change the paint’s PVC, keeping it near or slightly below the cPVC.
- Adding a significant amount of paste medium to artists’ oil paint does not necessarily increase the oil ratio or reduce the PVC to a degree that would classify the mixture as “fat.” The extender pigments maintain a relatively balanced oil-to-pigment ratio close to the cPVC.
- As a result, even when substantial amounts of paste medium are added, the excess oil introduced into the paint mixture remains minimal, keeping the mixture relatively “lean.”
Oil Painting Mediums (without extender pigments):
- These mediums contain only oil and resin (binder solids), possibly with solvents, but lack extender pigments.
- Adding even a small amount of this type of medium significantly increases the oil content, raising the ratio of oil to pigment in the paint mixture and, hence, lowering the PVC of the paint mixture.
- Without extender pigments, the binder-to-pigment ratio rises quickly, making the paint “fat.”
How cPVC Affects the Fat-Over-Lean Rule
The fat-over-lean rule requires successive layers of oil paint to contain more oil than the layers beneath, ensuring flexibility and reducing the risk of cracking. Critical Pigment Volume Concentration (cPVC) adds a crucial dimension to this rule by revealing how paint composition influences film properties beyond just oil content. The cPVC represents the threshold at which there is enough binder (oil) to fully saturate the pigments, creating a cohesive paint film. When the PVC exceeds the cPVC, voids form within the paint film, leading to brittleness and reduced gloss.
A question from one of our readers:
George, just read your latest fat/lean article. Great stuff but I have one question: Would “Oleogel” be considered a “paste” type medium? Wondering since it’s a bit thixotropic.
That’s a good question. Oleogel is not a paste medium. It is a gel medium. What distinguishes paste mediums from gel and liquid mediums is that they do not contain any pigments or extender pigments (fillers). Although Oleogel contains fumed silica, fumed silica is not an extender pigment, but rather an additive, since it does not provide sufficient solids to affect the pigment volume concentration (PVC).
Hi George, does all paint out of tube are considered equal “fat” since they are all close it it’s cPVC? However, I confused that some paint contains much more oil, doesn’t these paint is fatter than others, thus had to use in upper layers?
Thank you very much, lots of info that will be read and re-read.
Tighe
It won’t accept my website so here it is http://www.zin-uru.art
Hey there.
paintingbestpractices.com, It’s clear you put real effort into your site—thank you.
I recently published my ebooks and training videos on
https://www.hotelreceptionisttraining.com/
They feel like a hidden gem for anyone interested in hotel and management. These ebooks and videos have already been welcomed and found very useful by students in Russia, the USA, France, the UK, Australia, Spain, and Vietnam—helping learners and professionals strengthen their real hotel reception skills. I believe visitors and readers here might also find them practical and inspiring.
Unlike many resources that stay only on theory, this ebook and training video set is closely connected to today’s hotel business. It comes with full step-by-step training videos that guide learners through real front desk guest service situations—showing exactly how to welcome, assist, and serve hotel guests in a professional way. That’s what makes these materials special: they combine academic knowledge with real practice.
With respect to the owners of paintingbestpractices.com who keep this platform alive, I kindly ask to share this small contribution. For readers and visitors, these skills and interview tips can truly help anyone interested in becoming a hotel receptionist prepare with confidence and secure a good job at hotels and resorts worldwide. If found suitable, I’d be grateful for it to remain here so it can reach those who need it.
Why These Ebooks and Training Videos Are Special
They uniquely combine academic pathways such as a bachelor of hospitality management or a master’s degree in hospitality management with very practical guidance on the hotel front desk job duties. They also cover the hotel front desk job description, and detailed hotel front desk duties and responsibilities.
The materials go further by explaining the reservation systems in hotels, hotel check-in, check-out flow, guest relations, and dealing with guest complaints—covering nearly every situation that arises in the daily business of hotel reception.
Beyond theory, my ebooks and training videos connect the academic side of resort management with the real-life practice of hotel front desk duties.
– For students and readers: they bridge classroom study with career preparation, showing how hotel and management course theory link directly to front desk skills.
– For professionals and community visitors: they support career growth through questions for reception interview, with step-by-step interview questions for receptionist with answers. There’s also guidance on writing a strong receptionist job description for resume.
As someone who has taught resort management for nearly 30 years, I rarely see materials that balance the academic foundation with the day-to-day hotel front desk job responsibilities so effectively. This training not only teaches but also simulates real hotel reception challenges—making it as close to on-the-job learning as possible, while still providing structured guidance.
I hope the owners of paintingbestpractices.com, and the readers/visitors of paintingbestpractices.com, will support my ebooks and training videos so more people can access the information and gain the essential skills needed to become a professional hotel receptionist in any hotel or resort worldwide.
Either way, thank you, paintingbestpractices.com, for maintaining such a respectful space online.
Hello, friend!
paintingbestpractices.com, It’s clear you put real effort into your site—thank you.
I recently published my ebooks and training videos on
https://www.hotelreceptionisttraining.com/
They feel like a standout resource for anyone interested in hospitality management studies. These ebooks and videos have already been welcomed and found very useful by students in Russia, the USA, France, the UK, Australia, Spain, and Vietnam—helping learners and professionals strengthen their real hotel reception skills. I believe visitors and readers here might also find them practical and inspiring.
Unlike many resources that stay only on theory, this ebook and training video set is closely connected to today’s hotel business. It comes with full step-by-step training videos that guide learners through real front desk guest service situations—showing exactly how to welcome, assist, and serve hotel guests in a professional way. That’s what makes these materials special: they combine academic knowledge with real practice.
With respect to the owners of paintingbestpractices.com who keep this platform alive, I kindly ask to share this small contribution. For readers and visitors, these skills and interview tips can truly help anyone interested in becoming a hotel receptionist prepare with confidence and secure a good job at hotels and resorts worldwide. If found suitable, I’d be grateful for it to remain here so it can reach those who need it.
Why These Ebooks and Training Videos Are Special
They uniquely combine academic pathways such as a bachelor of hospitality management or a advanced hotel management course with very practical guidance on the hotel front desk job duties. They also cover the hotel front desk receptionist job description, and detailed hotel front desk tasks.
The materials go further by explaining the reservation systems in hotels, hotel check-in, check-out flow, guest service handling, and practical guest service recovery—covering nearly every situation that arises in the daily business of a front office operation.
Beyond theory, my ebooks and training videos connect the academic side of resort management with the real-life practice of hotel front desk duties and responsibilities.
– For students and readers: they bridge classroom study with career preparation, showing how hotel and management course theory link directly to front desk skills.
– For professionals and community visitors: they support career growth through interview tips for receptionist, with step-by-step questions to ask a receptionist in an interview. There’s also guidance on writing a strong receptionist job description for resume.
As someone who has taught resort management for nearly 30 years, I rarely see materials that balance the academic foundation with the day-to-day hotel front desk job requirements so effectively. This training not only teaches but also simulates real hotel reception challenges—making it as close to on-the-job learning as possible, while still providing structured guidance.
I hope the owners of paintingbestpractices.com, and the readers/visitors of paintingbestpractices.com, will support my ebooks and training videos so more people can access the information and gain the essential skills needed to become a professional hotel receptionist in any hotel or resort worldwide.
Appreciate you and your community.
[…] https://paintingbestpractices.com/fat-over-lean-in-oil-painting-best-practices-for-artists/ […]