Comparing similar colors – part 2

With all the similar blue watercolor colors available, which ones should you choose?  What qualities should you look for in the paint that’s right for you?

Last time, in part 1, I compared both several yellow paints and the most common brown paints.  In part 2 of this series, I’ll be comparing the colors and qualities of several popular blue watercolor paints, again using two of my favorite brandsWinsor Newton Professional Watercolors and Golden’s QoR Modern Watercolorsas examples.

Some of the qualities I’ll be considering are whether they are staining or not (whether they can be easily lifted off the paper), whether they are permanent or fugitive (having a tendency to fade or change color over time), how transparent or opaque they are, their comparative chroma (how “pure” or muted each color appears), and whether they have a warm or cool bias in comparison to other similar blues.

Blues:

Comparative chart - blues“French” ultramarine sometimes indicates that the color is slightly redder than other ultramarine alternatives in the same line.  It may also be designated as RS as opposed to slightly greener (GS) versions.  I find that ultramarine is difficult to photograph because the high-chroma pigment is so vibrant.  For this reason I tend to prefer the slightly lower chroma of the similarly warm-biased indanthrene/indanthrone (different brands spell it differently).  Cobalt blue tends to be the most evenly balanced between warm and cool so is a good choice for mixing.  Phthalo-based Winsor blue is available in two versions, a warmer (red shade—RS), and a cooler (green shade—GS).  The phthalo colors are excellent for mixing, but have strong staining power.

(Similarly, the phthalo-based Winsor greens—BS, blue shade, PG7 and YS, yellow shade, PG36—are so strong that they can easily get out of hand.  A much weaker cool green, viridian, PG18, is more muted and easier for inexperienced painters to control.  Don’t be fooled by a “viridian” made from PG7, a phthalo pigment!  Unfortunately, almost all green pigments are very difficult to lift.) I have not included greens extensively in this color-comparison series because they can be mixed from the other colors discussed here.  For more on greens, see my August 15, 2019 blog.

As you can see here, the same pigment is often used for several variations of color, dependent on the processing method used.  Different manufacturers may use very different names for the same color, or the same name for very different colors, so rely more on the pigments used than on the name, although the name may offer some clues.  As a general rule (with some notable exceptions) although the coloration may vary, other characteristics of the pigment will generally tend to be pretty consistent.  Many traditionally used pigments tend to be fugitive, while the more modern pigments have been developed to replicate them while remaining more permanent.

Such reformulated colors are often (though not always) referred to on the label as “hues.”  (Other “hues” have been formulated to replicate colors that traditionally relied on pigments that are either very expensive or are no longer available.)  Terms such as “permanent” or “new,” used within the name, usually indicate that this formulation replaces a similar but more fugitive color, which may or may not still be on the market.

Remember that these are just a few examples of only two brands of watercolor.  Similar colors of other brands will vary, depending on the pigment(s) used, formulation, and processing.  Read the labels or manufacturers’ information sheets for clues regarding transparency, permanence (lightfastness), and whether they are staining or non-staining.  Only direct comparison will determine temperature bias and chroma as related to similar colors.

-Lightfastness is often noted as ASTM I, II, III, or IV (the lower the number, the better—look for ASTM I or II), but not all pigments have an official rating.

-For clean mixing of colors (to minimize “mud”) look for transparent paints.

-For glazing, look for transparency, which allows underlying layers to shine through.  (Take note of how well underlying marks show through the paint in the chart.)

-Many organic pigments (quinacridone, phthalocyanine, indanthrone, etc.) tend to be transparent and have strong, staining characteristics.  Many (though not all) also tend to be more lightfast.

-Inorganics, such as cadmiums and earth colors (ground stone) are generally easier to lift off the paper but, because they are often granular, they tend to be somewhat less transparent.  But don’t expect any paint to lift entirely off the paper without leaving some color influence behind.

You are the best one to determine which qualities are most important to you and your working methods.  I hope these comparisons and tips help you in making wise selections for your own palette.

In part 3, I will be comparing a variety of reds.

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