MITRA Forum Question Details

The “rules” for painting are only guidelines. Almost all works of the works of the past contain some deviation from rigid best practices. The key is to keep the deviations small. Dark grounds (like the dark red or brown grounds found Spanish and Italian paintings from the 16th c on) are less flexible than white lead and can create major contrast shifts when the superimposed oil paint becomes more transparent over time. This does not mean that all works created on these types of grounds have been disasters. They have all probably altered in contrast in some manner, though. Even the use of a very heavy application of white for highlights means that it will be the mid-tones that darken the most with increased transparency. So it best to use a stable white ground, but fully realize that there are many, many examples where great masters of paining did not.

Umber and black have a very low pigment-volume-concentration (PVC) when mixed into a usable oil paint and are physically not the best options when used below stiffer and leaner upper layers. However, people have used umberfor underpainting both for its color but also because of its rapid drying due to its manganese component. This is less likely to cause major issues if used in conjunction with large amounts of a paint containing lead white. It is also not likely to cause problems if used as an outline to sketch in the composition. So while it is best practice to underpaint in more opaque high PVC colors, Rembrandt often did the complete opposite. We should realize that his works have altered some over time and, due to their universal esteem and value, are stored/housed in optimal conditions where they are monitored by conservators and other experts.

Rather than reinvent the wheel, I do think that the guidelines in this article are a good place to start (although #6 is confusing, I believe that they mean light in lower layers and darker in the upper).

https://www.naturalpigments.com/art-supply-education/simple-rules-oil-painting/

Again, these should be thought of as general principles that you may need to deviate from in some manner but only in small ways and for specific effects.

It's important to remember that some "rules" of ordering and layering may be based on the assumption that the artist will be using white passages in the first layers to pictorially communicate direct lighting. Not every artist will have that approach, even if it makes good sense in structural terms.

Many of the rules, including Rule #6, is based on the book Simple Rules for Oil Painting by A. P. Laurie. I was a little confused by it too, but I beleive it refers to building the entire painting in one direction, either dark to light or light to dark, but not in both directions in the layers.