Understanding Opacity, Transparency and Permanence for the Serious Oil Painter

Have you ever read on the back of a tube of paint and seen the permanence rating and wondered what it was or how to use that information?  Or have you ever wondered which colors make the best glazes?

These are important questions for the serious oil painter.  And much of this information needs to be committed to memory so that quick and quality decisions can be made in the studio.

 

Opacity
Opaque is explained in the Merriam-Webster Dictionary as “exhibiting opacity : blocking the passage of radiant energy and especially light”. As such, opaque pigments let less light through and allow better coverage in oil painting.  These are the colors that are the best for underpainting.  They cover quickly and throughly,  hiding or blocking any colors that are underneath them. 

Titanium white is a color that can be used to paint over or block out segments of a work in progress.  It can used instead of gesso. If you are not happy with a portion of your painting, just use this color to paint over it.  Once it is dry, you can start new with a surface that will be just like your underpainting.

 

Transparent or Lake Colors

Transparent colors also known as Lakes are explained in the same dictionary as “a. having the property of transmitting light without appreciable scattering so that bodies lying beyond are seen clearly; or b. fine or sheer enough to be seen through”.

Transparent pigments allow colors underneath to show through and are ideal for glazing.

I remember how surprised I was to learn that oil colors actually vary in the level of opacity. Some are more translucent, whereas some are more opaque than others. For example, there are several types of white pigments. Some of them are opaque, but some are transparent.

Unfortunately, there is no easy way to identify the opaque colors versus the transparent ones other than by memorization. To make it a little bit easier, I have compiled a list of common pigments divided into two sections; opaque and transparent.

Opaque
Cadmium Yellow
Cadmium Red
Cobalt Green
Ivory Black
Mars Black
Raw Umber
Titanium White
Vermillion
Zinc White (semi-opaque)

Transparent or Lake
Alizarin Crimson
Burnt Sienna
Cobalt Blue (semi-transparent)
Cobalt Violet (semi-transparent)
Davy’s Gray
Hansa Yellow
Phthalo Blue
Phthalo Green
Prussian Blue
Ultramarine Blue (semi-transparent)

 

Permanence
In simple words, permanence is how long the paint will last without fading.

For example, vegetable dies fade very fast but pigmented paint last much longer.  But pigment paints have different qualities and that’s why manufacturers have developed ratings.

Different companies use different codes. For example, Winsor Newton “AA” is the most permanent, “A” is second place but also good, then they have “B” and “C” that are not very permanent but are cheaper; but others brands use ” I ” to indicate the best and “II” the second place, so it can get confusing.

I was equally surprised to learn of a varying degree of colorfastness or permanence within the vast spectrum of oil colors. It seems to me that oil color is oil color, but that’s simply not true. Again, there is really no pattern to the colorfast quality of pigments. A good quality manufacturer will provide only the best pigments recommended as permanent for artists’ use, with a rating of “extremely permanent” or “permanent”. However, there are very few colors which do not reach this standard and are provided only because of the lack of permanent pigments in certain color areas. Sap Green and Carmine are examples of oil colors that are sold by manufacturers of fine oil paint but rate low on the permanence scale.

An artist may choose one pigment over a similar one because of the permanence rating. For example, Titanium White, Underpainting White and Zinc White all are rated by Winsor Newton as being extremely permanent (AA), but Foundation White and Flake White are only considered permanent (A).

Often a manufacturer will manipulate a pigment to offer an alternative to one with a weaker permanence. For example, Winsor Newton provides Permanent Sap Green with an A rating as an alternative to Sap Green, which they also sell but with a B rating (Moderately Durable).

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About Gary Bolyer Fine Art

I am a New York City-based landscape artist.
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