With blending medium they both look transparent to me except that sap has yellow in it. Maybe better to compare two yellows like stil de grain and a similar hued cad? Also, as a watercolorist I know sap green can have lightfastness problems depending on the yellow pigment used. Do R and F pigment sticks have lightfast ratings? If not are the pigment numbers available? For example, Alizarin crimson pigment pr83 in watercolor is not lightfast. Alizarin crimson in your pigment stick is beautiful and transparent, but is it made using a lightfast pigment or the fugitive pr83?
The Yellow pigment in our Sap Green is PY83, Disazo, or Diarylide Yellow. We list the chemical composition of all our colors on the labels as well as on our color chart and website. We do regular internal lightfast testing on our colors and we completed the only comprehensive lightfast tests (Arizona method) on encaustic paint several years ago. Unfortunately, this doesn't meet the ASTM standard D4303, which is designed more for oil, acrylic, and watercolor. The other serious issue with lightfastness ratings is that because of the cost and complexity involved, most companies have resorted to using the generic ratings created in the late 70s. Those ratings were not specific to any medium, and many have been retested and found to be inaccurate. While it certainly represents the low end of lightfastness in artist colors, we do use the pigment PR83 for Alizarin Crimson. Most manufacturers still offer a version of it and we recommend it not be used in tints. Otherwise it seems to perform adequately and there is great demand for it because of its unique properties.
I found this to be somewhat confusing. In the beginning you have the darker color on the left and then you switch it around and start talking about left and right colors in the copy. One color is also a prettier color than the other with more vibrancy so of course when you dilute it, it will still be a nice vibrant color. Frankly, I do not think that the example is a good one.
Hi Nancy. We're sorry you found this demo confusing. Our intention is to provide free and useful information for our viewing audience. You might find it helpful to check out the accompanying blog post with step by step instructions. www.rfpaints.com/unique-color/2021/3/25/demo-video-transparency-amp-opacity.
With blending medium they both look transparent to me except that sap has yellow in it. Maybe better to compare two yellows like stil de grain and a similar hued cad?
Also, as a watercolorist I know sap green can have lightfastness problems depending on the yellow pigment used. Do R and F pigment sticks have lightfast ratings? If not are the pigment numbers available? For example, Alizarin crimson pigment pr83 in watercolor is not lightfast. Alizarin crimson in your pigment stick is beautiful and transparent, but is it made using a lightfast pigment or the fugitive pr83?
The Yellow pigment in our Sap Green is PY83, Disazo, or Diarylide Yellow. We list the chemical composition of all our colors on the labels as well as on our color chart and website.
We do regular internal lightfast testing on our colors and we completed the only comprehensive lightfast tests (Arizona method) on encaustic paint several years ago. Unfortunately, this doesn't meet the ASTM standard D4303, which is designed more for oil, acrylic, and watercolor. The other serious issue with lightfastness ratings is that because of the cost and complexity involved, most companies have resorted to using the generic ratings created in the late 70s. Those ratings were not specific to any medium, and many have been retested and found to be inaccurate.
While it certainly represents the low end of lightfastness in artist colors, we do use the pigment PR83 for Alizarin Crimson. Most manufacturers still offer a version of it and we recommend it not be used in tints. Otherwise it seems to perform adequately and there is great demand for it because of its unique properties.
I found this to be somewhat confusing. In the beginning you have the darker color on the left and then you switch it around and start talking about left and right colors in the copy. One color is also a prettier color than the other with more vibrancy so of course when you dilute it, it will still be a nice vibrant color. Frankly, I do not think that the example is a good one.
Hi Nancy. We're sorry you found this demo confusing. Our intention is to provide free and useful information for our viewing audience. You might find it helpful to check out the accompanying blog post with step by step instructions. www.rfpaints.com/unique-color/2021/3/25/demo-video-transparency-amp-opacity.
Agree demo is flipped in end...confusing