Buckthorn yellow 2016

This year I decided to try using concepts from De Arte Illuminandi to try unripe, green berries to make yellow, a possibility indicated by the translators.

Two pigments were and are derived from Rhamnus berries; a yellow and a green.  The product of the unripe berries is the Giallo santo (cf. M. P. Merrifield, op cit., I clxiv), known in English by the extraordinary names, "Italian Pink" and "Dutch Pink."(Thompson and Hamilton 43)

That page of Merrifield's text explains,

 Giallo santo was a kind of yellow lake, which was made from various plants.  It was sometimes prepared from the berries of buckthorn (Merrifield clxiv)

and the result is reinforced by the Pigment Compendium that explains,

various species of the Rhamnacea family give a yellow dye on extraction of the unripe berries (drupes)

 It seems that the medieval artists more commonly would have probably used the local ochers from the land or orpiment, arsenic sulfide, or one of the lead yellows... but I have buckthorn berries from Saco, that I picked, for free, and don't feel like playing with arsenic or lead today!  

Here's a preview picture of them, 

yellow clothlets from green buckthorn berries in the foreground, sap green clothlets behind

And now I'll explain how I made them, just click 'read more' below.

I had a few minutes when I stopped at the old house in Saco to water the garden at the end of August so I wandered across the street to the abandoned lot and picked a few handfuls of green buckthorn berries.

I didn't have time to deal with them right then so I threw the baggie into the fridge.  First I used the ripe berries I picked the following week to make sap green clothlets.

As always, safety first! 

Adrienne's Experiment steps:

Research

Collect materials

SAFETY FIRST...

Suit up with nitrile gloves, goggles over glasses and mask!

 

We're dealing with some toxic chemicals here, please don't breathe in lye or alum. 

Then I cleaned out my "glazed porringer" and, after a rest, set about following De Arte Illuminandi again, substituting the unripe, green berries.  Here's that recipe again:

De Arte Illuminandi pg. 7

I picked out the leaves and used all of the berries, 31.75g.  Most were bright green, a few had turned red during the week of my procrastination but I decided to go for it anyway.  This is a hobby after all, I hope no one will hold it against me! ;) 

Mostly green buckthorn berries

I poured them into a clean, boiling-water-bath-sterilized ball jar and crushed them with gloved hands.

Added 32g Distilled Water (DW), to 4.08g lye, K₂CO_3, or, actually, the other way around.  Sorry to be a pest, but, pretty much always add chemical to greater volume water than water to chemical.  Miss Safety again... complain at me later.

So, anyway, once I mixed my lye into the water, I put it on the simmer burner to dissolve and measured 1.68g aluminum potassium sulfate (alum).  When I introduced the alum to the lye water at 128oF it caused an immediate bubbling and the temperature rose to 138oF.  Fairly confident the chemicals had mostly dissolved after it had raised to 14oF, I mixed it with a disposable chopstick and poured it over the crushed green berries.

As the treatise says, I mixed it once and proceeded to walk away from it for three days.  Again, the laundry room, quiet, clean and undisturbed while I played with my new kitten!

After three days I poured it into a funnel lined with cheesecloth, picked up the cloth by all four corners and squeezed the liquid into a new sterilized ball jar.  26.58g of bright yellow liquid! Achievement!  It says I can make clothlets with it or keep it in a closed jar, so I do both.

To make the clothlets, I first dipped pieces of scoured 'natural' linen from the fabric store in 1:15 aluminum potassium sulfate water and let it dry under a fan, twice, while I was waiting the three days until the berry juice was ready.  When the yellow juice from the green berries was squeezed out of them, I discarded the seeds in the trash.  Buckthorn is invasive to North America so I'd rather not add them to my compost pile...

yellow cheesecloth used to squeeze berries

Using the alum prepared clothlets, I saturated them with yellow berry juice, squeezed out the excess and laid them out to dry.  I set up an indirect fan walked away.  Unfortunately the light is on the same circuit as the fan so both stayed on.  For this experiment the color is so intense I only dipped and dried twice before they looked ready!

After the event on Saturday (or maybe at the event?), I'll snip a piece of the clothlet, add gum Arabic water or glair and see how it paints out.