Another perplexity is in regard to the Burnt Madder. If the madders are in themselves sound colours, as I have always understood them to be, how do they lose their permanence by burning? I should like to use the Gialetto, and I rather gather from what you say that I may do so. I hear with interest what you tell me of your new varnish. As for myself, I have got to dislike the use of any resins in my work to such an extent that I have completely set them aside. Of course when a picture is finished it requires some gum, not only to protect it, but to bring up the colour to its full value. Will you let me know—but this will do at your leisure, for the time has not come yet—whether a picture being painted as I paint mine, exclusively with Bell's medium and turpentine from first to last, and, I may add, worked on up to the last moment of sending in, i.e. a fortnight later, may on the walls of the Academy be safely varnished with this new material of yours, either alone or diluted with a little poppy oil? I look forward with interest to Heyl's Madder Green.
December 5, 1891.
I shall certainly try the Heyl's Madder Green, which I hear of through you for the first time. Laurie's daffodil cadmium is very pretty. I have got some; but my new delight now is yellow cobalt, which you have found to be absolutely safe, and which is absolutely delightful as a colour.
My tempera is come from Italy, and I am told that it is made of the tails (feelers?) of the cuttle-fish (sepia). Would you like to look at it again from curiosity? I understand that with the reservation that it darkens, I may use it with impunity in, under, and with the oil—that is enough for my purpose.
October 16, 1894.
Will you kindly advise me on the tempera, of which I send a tube? It is used by my friend, Prof. Costa, who gave it me; he likes it vastly. It coalesces with oil; he uses it also by itself between two paintings in oil. I have often longed for something to keep down the greasiness and slipperiness of oil paint when correcting or going over a surface often, oil and water do coalesce sufficiently. The most luminous thing I ever painted (and it has stood like a rock) was painted (or certainly thickly underpainted) with a vehicle made of starch and oil. What this medium is, I don't know. Please advise.