Transparency & Painting Shadows!!!

Transparency & Painting Shadows!!!

Rubens broke through the traditions of the earlier Flemings ; his vigorous temperament made him impatient of the constraints imposed by the saving at all hazards of the white negative ground. White pigment becomes with him a very active agent, and he reserves the white and sometimes light-grey ground to secure transparency in his shadows.

We are told on good authority that "Every- thing at first under the pencil of Rubens had the appearance of a glaze only."

One of his leading maxims respecting colour, which he repeated often in his school, was that "it was very dangerous to use white and black. Begin painting your shadows thinly, and be careful not to let white insinuate itself into them, as it is poison for a picture except in the lights. If white is ever allowed to dull the perfect transparency and golden warmth of your shadows, your colouring will be no longer glowing, but heavy and grey. The case was different in regard to the lights; in them the colour may be loaded as much as may be thought requisite. They have substance; it is necessary, however, to keep them pure. This is effected by laying each tint in its place, and the various tints next each other, so that by a slight blending with the brush they may be softened, passing one into the other without stirring them."

Few masters of the overpowering vigour of Rubens preserve the same methods throughout their career, and perforce adapt their process to the special demands of varying effects ; but there are certain guiding principles to which they remain faithful, and we may conclude that his brilliancy, and the luminosity that belongs equally to the work of his pupils Van Dyck and Jordaens, who was rather an assistant than a pupil, was largely due to the clear under-painting and the separate superimposing of more or less transparent colours.  (The Practice of Oil Painting by Solomon J. Solomon, p. 171, 172 & 175)

“Shadows in nature have a transparent quality that you will want to pay close attention to.  Study some of Rembrandt’s work and you will find that he kept his shadows very clean of any opque pigments.  In the lights, we want to build up our paint and try to capture the illusion of the surface being illuminated.  In the shadows, it is like it is lost in the darkness and takes on an airy quality.  A color may be able to retain this transparent quality if painted in a thin manner as well… [A] time where it might be necessary [to add white or opacity] to is if there is a reflected light and form created in the shadows turning them into dark halftones.” (Flower Painting by Michael Klein p. 42)

Rubens and Klein seem to be focused on the transparent nature of certain pigments couples with how thinly or thickly they are applied to the canvas; such practices may be mimicked to a certain extent in digital painting, but are by nature, more suited to actual oil painting. 

David Leffel’s interpretation of transparency and the nature of shadow may be more helpful to the digital artist, as he seems to emphasis color temperature and the flat/compressed nature of shadows:

“Put enough orange in that purple shadow you’re painting to make it shadowy, that is to say, warmer, and more transparent.”

“Accents are dark, descriptive strokes that are as important as highlights.”

“Besides structure, shadow provides design and color.  Design your shadow shapes.”

“Cast shadows provide an object with roots and stability and keep it from flating in midair.  They are an important structural unit.  They help describe the surface the object rests on.”

“Light is the foreground; all else is background.”

“Shadow means the absence of light; it is an absolute.  Yet shadows are rarely totally dark because light is usually reflected into them from nearby objects.  But reflected light does not always result in making shadows light.  Sometimes it makes the shadow appear darker by contrast. “

“In the shadow areas and the background, try to keep the values close together.”

“Darks get lighter as they go further back.  Light is more constant outdoors as well as indoors.”

“Make a richer statement with your shadows.  Use more cadmium colors – yellow, orange, red – with ivory black.  Cadmium colors create depth because they make things transparent, and the eye equates depth with transparency.  Opacity is the look of light.” (Oil Painting Secrets from a Master by Linda Cateura p.64)

Note: Cadmium pigments are actually some of the more opaque pigments, so Leffel seems to be describing a transparent effect with warm pigments painted flatly or thinly.

“In chiaroscuro painting, shadw and light have specific, unique functions.  They do not overlap.  The first masses painted onto the canvas are the shadows.  As monolithic entities, athese shadows or dark elements anchor the compositon.  They are quiet – still – mysterious.  They have no hard edges.

            Shadow is the absence of light.  Although the artist painting in the studio does not paint in toal darkness, the shaow areas of the subject matter, on the model or still-life, are the result of the absence of light. One cannot have more or less absence, for absence is absolute.  Once a value for shadowrepresenting a particular element in the painting is established, it cannot be painted darker, because it represents an absolute.  The quickest way to ruin a painting is to paint a dearker value into the value of shadow already established.

            The only factor that modifies shadow is reflected light.  Reflected light conveys the illusion of lighter and darker shadow, but it is only light reflecting into the shadow.  Dark and light materials have different values in the same shadow situation, and each must be relatively flat.  The illusion of form is not in, or conveyed by, shadow.  Instead, describing form is a function of light.”