Do "Hues" mix differently to actual pigments

[Einion]

Thanks for all the answers so far folks, I think we've covered all the usual areas when the subject of hues come up - including one of the ones that's often overlooked, that hues aren't necessarily inferior to the original paint they substitute for. They can sometimes be better in certain ways, occasionally in all ways.

Carolyn, to add some things on a couple of your specific points:

Originally Posted by AbstractArt99

If so, are student grade paint "hues" and convenience mixes actually a hindrance? Should I be buying paints that only contain one pigment and learning to mix from those?

I think it's good general policy to actively seek out single-pigment paints and to prefer those in place of mixtures.

You don't have to take this to extremes and refuse to buy any mixtures just on principle, some mixtures could be worthwhile conveniences and useful to you. But it is worth bearing in mind that if a convenience colour is made from pigments that are available as single-pigment paints they are much more versatile than the mix.

Originally Posted by AbstractArt99

I guess my main concern is if I spend a lot of time learning to mix with student substitute hues, then when I move onto using artist grade paints I'm going to have a lot of relearning to do.

There is some inevitability of this I'm afraid. This is inherent to painting more broadly than just with hues versus the genuine article. Different versions of 'the same' colour can be quite different in some cases, as mentioned in a couple of ways above. I can remember vividly the problem I had dealing with a version of Raw Umber in a new brand because it was almost completely unalike the one I had previously been used to; it wasn't just that they were very different in colour, they had very different consistencies and opacities too.

Einion

[Termini.]

Originally Posted by Einion

I think it's good general policy to actively seek out single-pigment paints and to prefer those in place of mixtures.

Yes, and there are many including the quinacridones, and pyrroles, that are not super expensive, yet excellent in most ways.

[sidbledsoe]

Though I would pretty much agree with preferring single pigments as a rule of thumb, there are as always a couple of exceptions, titanium/zinc white is a mixed pigment that is generally preferred, for general painting, over either one in single pigment form, though it isn't because of color issues like you are talking about. Some think a mixed chromatic black is richer or more "colorful" than plain old single pigment black.

[AbstractArt99]

Thanks for all the answers everyone. I have been inspired to look more closely at the pigments that go into each paint and compare between brands.

It's interesting to note not only the differences, but also the different colours that use the same pigments.

ie. Winsor and Newton Burnt sienna, indian red, light red, mars violet deep, terra rosa, transparent red ochre, transparent brown oxide and venetian red are all made from PR101 red iron oxide.

[Einion]

Originally Posted by AbstractArt99

Thanks for all the answers everyone. I have been inspired to look more closely at the pigments that go into each paint and compare between brands.

Just to mention again something in relation to differences, don't expect that the same listed pigment will be the same from brand to brand. PR101 may be the most varied of all but many pigments vary quite a bit, cadmium red being one of the key examples. But even something that's thought to be fairly consistent, Phthalo Blue GS, can be surprisingly different from one range to the next.

Einion

[Gigalot]

Originally Posted by Einion

[IMG]
Phthalo Blue GS, can be surprisingly different from one range to the next.

Einion

Because Phthalo Blue GS actually is a mixture of two crystal form - beta phtalocyanine with more or less reddish alpha phtalocyanne content.

Green Phthalocyanine has only one form and it`s color less different.

[sidbledsoe]

Originally Posted by Gigalot

Green Phthalocyanine has only one form and it`s color less different.

I know of at least two forms, chlorinated which yeilds a blue shade, and brominated which yeilds a yellow shade. If you mean within one of those particular shades of phthalo green that there is less variation than the variation within one particular shade of phthalo blue then I guess that could be true.

[Gigalot]

Yes, brominated phthalo green is a chemically different green form PG36 while Phthalo blue beta and alpha are only physically different crystalline forms.
During Phthalo Blue GS manufacturing process more or less greenish beta form converts to a reddish alpha crystals.

Naphthol AS PR170 (less popular pigment than Phthalo ) has also many hue variations because it consists of several different forms.