Home Forums The Learning Center Color Theory and Mixing Hansa Yellow PY3, PY74 do you use them? (lightfastness II)

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  • #989458
    Marigold
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        Hello,
        My question is in the title. I got a whole assortment of Lefranc & Bourgeois Artist oils on closeout for an incredible price. Amoung them are 2 tubes of “Japanese Yellow”, one is PY3 and one is PY74.

        These Pigments apparently have not the highest ratings for lightfastness.

        DickBlick says:
        PY3 – fair to good permanence
        PY74 – better lightfastness than other yellow monoazo pigments

        Here the swatches:
        Lefranc Japanese Yellow Lemon PY3
        Lefranc Japanese Yellow Light PY74

        So I was wondering what you guys think. I know PY3 is widely used as lemon yellow… So in your experience, how serious are the lightfastness problems with these two arylide yellows? Should I better not use these paints?

        Thanks
        Susanne

        #1157826
        Gigalot
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            My PY3 is fugitive in tints, but can be 20-100 times more lightfast in masstone. However, PY74 is better. Use it thickly :) I guess, it is good enough to impasto painting. And , also why not to use such a non-toxic and fast drying paints as a Cadmium Yellow underpainting during you try to build composition? You can save some money and time.

            You can remember, how many famous painters used a very fugitive indigo pigment under brilliant lapis lazuli in the past!

            #1157822
            Marigold
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                And , also why not to use such a non-toxic and fast drying paints as a Cadmium Yellow underpainting during you try to build composition? You can save some money and time.[/quote]
                That is a very good idea, thanks! I will keep that in mind (although I am never sure how much or little of my underpainting will be covered in the end)

                My PY3 is fugitive in tints, but can be 20-100 times more lightfast in masstone. However, PY74 is better. I guess, it is good enough to impasto painting.[/QUOTE]
                That’s good to know, but then… what use is a color that I cannot use in tints? The larger part of most paintings are tints aren’t they.

                Susanne

                #1157827
                Gigalot
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                    Cadmium is better in tints, much better. But, you can also use thin white layer over Hansa layer to make a tint-looking glaze. Why not?

                    #1157811

                    Yes and yes. Even though I use it I’m not especially fond on PY3 but PY74 is one of my favourite synthetic-organic yellow pigments, possibly second only to PY110.

                    PY3 was one of the things that led me to do my first lightfastness tests for acrylics, because I had concerns about the long-term performance of two pigments I’d been using for many years (this and PR170; both did more than well enough for me incidentally).

                    The lightfastness of PY3 and PY74 is generally acceptable in watercolour and nearly every pigment performs much better in an oil binder so there’s a reasonable expectation that oil paints made from them would be fine to use for most people.

                    Just generally though, lightfastness for many pigments varies and stock ASTM lightfastness ratings are often what are listed, which may not accurately reflect the reliability of individual paints. Sometimes it’ll actually be better (occasionally much better), other times worse (sometimes by quite a bit unfortunately).

                    Both of these yellows unfortunately can have a wide variation in how well they stand up to light.

                    If you’re particularly concerned with permanence issues like this the only way to reassure yourself is to do some of your own lightfastness tests – with the paint tested by itself and mixed 1:10 with Titanium White, applied in a moderate impasto as well as brushed out thinly.

                    Einion

                    Do you know if your colour is off in hue, value, chroma... or all three?

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                    #1157812

                    My PY3 is fugitive in tints…

                    Can be Alex, can be. As I’ve mentioned before, other versions than the one you’ve tested perform much better.

                    Einion

                    Do you know if your colour is off in hue, value, chroma... or all three?

                    Colour Theory & Mixing forum WetCanvas Glossary Search Tips Advanced Search Acrylics forum Acrylics - Information Kiosk

                    #1157828
                    Gigalot
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                        Einion, I just say one word in favor to Hansa – it can be a very effective oil film protector against UV light. After my lightfastness test oil film painted with Hansa stay well, as other pigment painted oil films has a micro cracks and even decomposed on a strong light.

                        #1157823
                        Marigold
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                            Thank you Gigalot and Einion for your competent answers.

                            Yes and yes. Even though I use it I’m not especially fond on PY3 but PY74 is one of my favourite synthetic-organic yellow pigments, possibly second only to PY110.

                            This helps. My conclusion is that I will get another tube of the PY74, and use the PY3 with Caution.

                            The PY74 was in the older Lefranc version called “Flemish Yellow”, very fittingly I think because it resembles the beautiful lead-tin yellows (?) I have admired in some Dutch genre paintings. It is a very pleasant, more transparent and cooler than cadmium, but without a strong “lemon” tinge.

                            But, you can also use thin white layer over Hansa layer to make a tint-looking glaze. Why not?

                            Yes, why not :). Or the other way around, as it is semi-transparent. When it is said about a pigment that it is “less stable in tints”, is the fading caused by the intermixed white pigment, or by the relatively low density of the colored pigment? I other words, would a glaze that is pure yellow perform well even if it is very thin?

                            PY3 was one of the things that led me to do my first lightfastness tests for acrylics

                            Einion, I have heard you mention your PY3 test before, would you like to share your results in more detail?

                            Susanne

                            #1157829
                            Gigalot
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                                or by the relatively low density of the colored pigment? I other words, would a glaze that is pure yellow perform well even if it is very thin?
                                Susanne

                                Yes. Hansas has a tendency to be less lightfast in a low pigmented mixtures.
                                Different pigments has a different properties and lightfastness curve. :)
                                Transparent pigment form (as a rule) mostly has a much better lightfastness in a pure form than in tints. As an opaque form of the same pigment might be better or much better in tints but(!) often can loose in masstone. (Opaque vs transparent form)

                                According this, pure Hansa must be more lightfast even in a thin layer, than in a thick tints. But I did not make myself tests to compare.

                                Personaly, I trust 1:1 and 1:2 tints, but try to avoid 1:10 – 1:20 tints and use Cadmiums and Ocher instead Hansa.

                                #1157816
                                JPQ
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                                    My basic yellows are in aquarelle py3,py65 and py35 (cadmium medium yellow). actually i must buy next time i thnk py3 (artist quality paint now i have good student stuff)… and good know these are problematic looks llike i must think other colours replace this py3. maybe winsor yellow and winsor lemon.

                                    #1157830
                                    Gigalot
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                                        Mostly, I use Strontium yellow PY32 (only in oil) from St. Petersburg instead of PY3 in all mixtures (except mixture with Cadmiums because I try to avoid chromium pigments to contact with sulphuric substances) .

                                        No visible changes happened with PY32 after 2 years sunlight outdoor test. It is a very common lemon yellow in Russia, you might get it easily :)
                                        PY175 Bensimidazolone yellow said to be more lightfast than PY3 but dull in tints.

                                        #1157813

                                        Einion, I have heard you mention your PY3 test before, would you like to share your results in more detail?

                                        There’s not really much to tell, since the PY3 held up fine! :) I’d have to check my notes (on another computer) to get more specifics but basically every paint in artists’ acrylics that I use commonly performed well enough that I have no hesitation in using them, including the two I was particularly worried about as I mention above.

                                        A bit of detail on the test I ran in this old post.

                                        Einion

                                        Do you know if your colour is off in hue, value, chroma... or all three?

                                        Colour Theory & Mixing forum WetCanvas Glossary Search Tips Advanced Search Acrylics forum Acrylics - Information Kiosk

                                        #1157839
                                        AaronGal
                                        Default

                                            PY3 Hansagelb gehört zu den farbstärksten Pigmenten. Die Lichtbeständigkeit ist von Firma zu Firma unterschiedlich, wie bei allen anderen Pigmenten auch.
                                            Niemand kann zu einem unbekannten Produkt generell Auskunft geben, das ist unmöglich.

                                            #1157817
                                            JPQ
                                            Default

                                                Mostly, I use Strontium yellow PY32 (only in oil) from St. Petersburg instead of PY3 in all mixtures (except mixture with Cadmiums because I try to avoid chromium pigments to contact with sulphuric substances) .

                                                No visible changes happened with PY32 after 2 years sunlight outdoor test. It is a very common lemon yellow in Russia, you might get it easily :)
                                                PY175 Bensimidazolone yellow said to be more lightfast than PY3 but dull in tints.

                                                I never heeared this pigmetn before. i mean PY32. and st peterburgs gives only one star for it.

                                                #1157831
                                                Gigalot
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                                                    They gives a low rating to it because some old painters said it can turns green in mixture. But modern tests gives ASTM I rating to PY32. It is most permanent colour from chromate pigments rank, much better than chrome yellow (which can stay well 100 or more years in Gaugin`s painting, but also darken rapidly in Van Gogh`s paintings). A suspected substance which can affect it is sulphates or sulphuric contain pigments. Therefore, I tried not to mix it with Cadmiums. I guess, PY32 is more weatherfast pigment than Cadmiums. Barium yellow and Strontium yellow both are good enough (Turners yellow and Lemon yellow). But Barium yellow is pale yellow pigment. Strontium has saturated lemon color and looks very close to Hansa PY3.

                                                    http://www.artiscreation.com/yellow.html#PY32

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