Viewing Topic "Lapis Lazuli"
I haven't yet heard from my painting friend where she got her info on lapis, but glad to hear it's not a problem in tempera - I'll reassure her. Thanks, Koo
My question for you is does the artist make this statement based on experience or reading? It is true that both ultramarine blue and lazurite (lapis lazuli) may gray out due to either what is known as "ultramarine sickness" or another issue recently identified by conservation scientists as disintegration of the binder around pigment particles due to the poor wetting ability of these pigments, both of which only occur in oil paint. I am not aware of any problem of this nature in egg tempera.
A fellow tempera painter recently told me that "Afghan lapis lazuli will grey out" with age. I understand that less well-washed grades of lapis have much less blue chroma and appear greyish from the start; and I've heard that acidic conditions can dull a genuine lapis lazuli to grey. But I haven't heard of a high grade lapis lazuli pigment turning grey merely from aging. Your thoughts?