Editing Fat over lean (section)

{{Short description|Style of oil painting}}
'''Fat over lean''' refers to the principle in [[oil painting]] of applying [[paint]] with a higher oil to pigment [[ratio]] ('fat') over paint with a lower oil to pigment ratio ('lean') to ensure a stable paint film, since it is believed that the paint with the higher oil content remains more flexible.{{dead link|date=August 2020}}<ref>
{{cite book
|url=http://www.winsornewton.com/assets/ocb_english.pdf
|title=The Oil Colour Book
|publisher=Winsor & Newton
|year=2001
|page=75
|archive-url=https://web.archive.org/web/20110718064125/http://www.winsornewton.com/assets/ocb_english.pdf
|archive-date=2011-07-18
}}</ref>

[[Oil paint]] dries at different rates due to the differing drying properties of the constituent pigment. However, everything else being equal, the higher the oil to pigment ratio, the longer the oil binder will take to oxidize, and the more flexible the paint film will be. Conversely, the lower the oil content, the faster the paint dries, and the more [[brittle]] it will be. Ignoring this practice, even in some ''[[alla prima]]'' painting, may result in a cracked and less durable paint film.{{dead link|date=August 2020}}<ref>
{{cite book
|url=http://www.randomhouse.com/catalog/display.pperl?isbn=9780823030668
|title=Traditional Oil Painting
|publisher=Watson-Guptill Publications
|year=2007
}}</ref>

It has been claimed by some paint manufacturers{{who|date=November 2010}} that the 'fat-over-lean' principle can be circumvented by using synthetic, alkyd-based painting media such as Galkyd and Liquin. These media do provide consistent drying times, increase the paint film flexibility, and promote adhesion between paint layers. However, because classical painting media, turpentine, natural resins, and certain plant oils ([[linseed oil|linseed]], [[walnut oil|walnut]] and [[poppyseed oil|poppy]]) have lasted for centuries when applied properly, some artists choose to avoid synthetic media since their long-term stability is unknown.