The recipe I have attempted is from the Paduan Manuscript via Mary P. Merrifield’s Medieval and Renaissance Treatises on the Arts of Painting. (1999). I haven’t managed to get a workable-for-me version of the original manuscript source, but the Manuscript Miscellanea 992 contains recipes for all kind of colours, fine inks, and varnishes, gum arabic, and instructions on how to gild book papers, to make acqua forte, “to make paper as transparent as glass”, to print and paint on glass and to gild on glass, and “to make undulating turkish paper in several colours” (this, I think, is paper marbling, which I adore) – it sounds awesome, to be honest, between my favourite interests in inks and pigments, paper and glasswork it sounds right up my street and I want a more complete version. But for now, Buckthorn Ink
31. How pasta verde [sap green] is made. – Take the grains or berries of the buckthorn when they are quite ripe, and this will be about the end of September; let them soften for 7 or 8 days in a vase with water in which roche alum has been dissolved in the proportion of 1 ounce of alum to 6 of the berries, and boil it well until nearly half the water is consumed; then cool it, strain it through a linen cloth, put the part that is strained into pigs’ bladders, and dry them in the sun or smoke; and this is called “pasta di vesicha.”Merrifield, Medieval and Renaissance Treatises on the Arts of Painting 662
I’ve mentioned on more than one occasion that buckthorn is hard enough to find here. It is a tree that apparently likes damp ground, so there should be plenty where I live but I have only found one, but luckily it’s a good size tree. The eagle eyed amoung you will probably recognise that it is August, not September. I haven’t harvested from the tree yet, but I found a supplier that sells the dried ripe berries and decided to experiment with those before I (hopefully) get to the fresh ones. It’s been easily 7 days since I started them soaking in half a litre of water with 16grams of alum (1/6th of the weight of berries I had.) It went a nice green colour very quickly, but none of it really shows that well in the photographs. The berries in water alone had a yellow-yellow green hue, but the minute alum was added the green became far more pronounced.
Roche Alum aka roche allam; roch allum; roch allome; roch allom; roack allom; roach-allum; roach allum; roach allome, Rock alum or Roman alum, was ALUM prepared from the alum-stone in Italy. When we try to recreate medieval work with pigments and dyes the alum we need is Potassium aluminum sulfate (KAI(SO4)2) or alum-(K). Potassium alum is also known as potash alum and is used for pickling and in baking powder. It is also used in leather tanning and dyeing. There are also sodium and aluminum alums which are not what we need so make sure you pick up the right one.
The recipe calls for the strained liquid to be reduced by half. I kept it on a low simmer ’til this was achieved. There was a lovely color swirled up occasionally on the sides of the pan and, surprisingly, a quite appetising smell, not unlike when I made elderberry wine in the past.
Again, the photographs have utterly failed to capture the intensity of the colour here, which is a shame. I hope I’ll have better luck when I try out the ink on test paper later. I have decided to go with four small bottles (herb jars) and to try one just as it is, one with a clove added (medieval trick against spoiling) one with extra alum and one with calcium carbonate (as chalk) added. Why chalk? because of my second recipe and it’s variants from the early XVth century Segreti per Colori (Secrets for making colors)
To make a good green with buckthorn.-Original treatises, dating from the XIIth to XVIIIth centuries on the arts of painting, in oil, miniature, mosaic, and on glass; of gilding, dyeing, and the preparation of colours and artificial gems; preceded by a general introduction; with translations,prefaces, and notes. Merrifield, Mary P. p. 420.
Take small berries of buckthorn when quite ripe, put them into a glass vase, and crush them well with
your hands; then place them in the sun, and let them remain until the juice rises above the berries; then strain the refuse, and throw it away, and if the juice weighs one pound put into it the weight of two quattrini* of roche alum in powder. Place the mixture in the sun in a well-closed glass vase, and let it stand three or four days, stirring it well three or four times every day; and if it should happen to dry after a time, distemper it with clear ley, with a little gum.
A quattrini, for those dying to know, was a small coper coin, a 60th part of a Florentine lira; I do not currently have such a thing to weigh, I assume if we could find a coin we could weigh it for an actual value. Maybe I should try to find a medieval quatrrini. OKay, one quick internet rabbithole later, here’s a quattrino from 1560 – it says this particular coin weighs 0.68g But whatever, not knowing put me off using this recipe to try BUT I was interested to note that this basic buckthorn recipe was augmented with added chalk (or calcium carbonate) to precipitate the color, and potassium carbonate was added to another two. I don’t have potassium carbonate right now to experiment with, but I do have chalk, so potassium carbonate next time.
For ages I had assumed that was pretty much it for buckthorn recipes- berries and alum, add chalk or potash salts as desired. But naturally just when I decide I have it sussed I find another one, this time with lye. This one will be my next attempt, as I want to see what difference it makes. It wants berries “which are gathered in the vintage season”
Take the aforesaid seeds or berries, put them into a glazed porringer, and break or crush them well with your fingers. then dissolve in clear lye, not too strong, as much rock alum as it will dissolve on the fire. And pour enough of this lye and alum over the berries in the porringer to cover these berries, crushed as directed. And let them stand so, out of the way, for three days, and then wring them out with your hands in a linen cloth*, and strain the juice into another glazed porringer. And if you want, you can keep it in linen cloths; do throughout as directed above for the juice of the lilies. But otherwise put it into a glass bottle, and keep it by sealing the bottle.De arte illuminandi
* Linen cloth here probably refers to clothlets, which I will be discussing in my next post. They are pigment infused linen pieces that can be stored dry and wetted with suitable liquids to use the pigment later.
Swatches and tests of an unscientific nature… More yellow than green I guess, but quite nice in it’s way. I will do some research to see if I can make a greener version.