Is Ultramarine Blue warm or cool? 🔥❄️

[@BobStrawn]

My feel for ultramarine is that it is a granulating pigment so it can make little tiny dots instead of evenly covering. As a result, it does not act as the same sort of light filter as a non granulating pigment. So while a non granulating pigment might entirely block a range of wavelengths when mixed with another color and thus have the warm or cold effect in a mix, ultramarine can sit beside another pigment and let the warm or cold shine through while still imparting it's shade.

[@marcjasi]

@@BobStrawn interesting to read that! Never had such a feeling for ultramarine. Are you using it in oil paint? I know watercolor ultramarine tends to granulate. So I research about it and apparently the French ultramarine is more granulating than the normal ultramarine. Maybe if that’s an issue for you try the regular ultramarine. Trying other brands help as well. I heard Schminke has a “non granulating” ultramarine, but again not sure in what form, is that watercolor or oil or both. 🙏🏻

[@BobStrawn]

@@marcjasi I do use watercolors. Brushes last longer and less pigment goes down the sink. I was never able to stay clean when using oils. As far as granulation goes, some artists hate the granulation and others love it. For me it gives me another option for expression. It is even possible with some versions of ultramarine to control how much it granulates. There is another possible reason why ultramarine might be perceived as warm or cold. Our brain uses data from three types of cone cells and they match more to greenish yellow, green and violet than they do to red, yellow and blue. The cones are labeled; L for long, M for medium and S for short wavelengths. The L is the one that people say is sensitive to red but it centers more on greenish yellow and it has jump in it's curve of sensitivity that makes it more sensitive to a lot of blue frequencies than it's sensitivity to a lot of red frequencies. There is a theory that that L-cone leap in sensitivity for blue is the cause of our perception of light going from blue to red making a color circle, when the frequencies of light go from far red to far blue and there is no circle of color. A lot of charts fudge their data and show even curves, but the more science based ones will give a few more clues about the frequencies our eyes respond to. This one is a bit better for the curves than most. www.pixelsham.com/2016/03/10/sensitivity-of-human-eye/ That bump in sensitivity might also make the warm/cold perception of ultramarine a bit more complicated.

[@marcjasi]

@ very interesting thank you for sharing 🙏🏻 I have a video about how I clean my brushes in case one day you want to try oils again

[@sylvain_st_pierre_2019]

Très intéressant. Merci

[@marcjasi]

@@sylvain_st_pierre_2019 avec plaisir 🙏🏻

[@Ahmed.muharam]

Compared to what?

[@marcjasi]

@@Ahmed.muharam please watch the video 🙏🏻