2016 Buckthorn with vinegar paint results

Here are the paint results from these buckthorn and vinegar recipes in 2016.

 

I was able to make a nice sap green from the buckthorn with white wine vinegar by adding a little potassium aluminum sulfate (alum).

Note that the 25% acidic vinegar and buckthorn produced a thick juice that required more thinning and would require more water and more gum Arabic to produce a smooth paint.

When I added alum to both buckthorn and vinegar recipe it resulted in green!  By itself, the results were less satisfying and not what I would call green but more blue gray.

Side note: I think the shininess on the first two swatches is the result of a little too much gum Arabic.

Buckthorn with vinegar, twice in 2016

In 2016 I tried twice more to get green for paint or dye/stain from buckthorn.

Bolognese MS De Tintis ad Tigendum Pellum (Merrifield 426)

2016 sap green from Buckthorn Experiment 2 Results

This experiment began in November 2016 and was finished up at the beginning of 2017.

The ripe buckthorn, Rhamnus spp., juice had been extracted from refrigerated, and slightly dessicated buckthorn berries from Saco, Maine. The berries were reconstituted with distilled water (DW), and then rock alum (potassium aluminum sulfate) was added to the juice.  Commercially available gum Arabic was then used with distilled water to paint it out on 12/23/16.

By 12/29/16 the dark blue had turned to dark green and further trials were performed. 

The change of color from blue to green suggests a few possibilities to me.  Either the alum had a chance to change the buckthorn after sitting with it for a while or it could have come into contact with calcium carbonate contaminates from the enviornment like egg or clam shell (neither of which are scarce in my house) or the Strathmore Bristol vellum finish paper is prepared with a buffer that reacted with the acids and berry juice. 

Further trials were painted out from the original berry juice with alum in the palette and shell with gum.  More distilled water was used to re-hydrate the paint and thin it out for greater visibility.

The juice with alum alone, in a clam shell and with crushed egg shell all yield what I would describe as a gentle sap green.  The trial with lye turned from a rather interesting olive to quite a bright yellow reminiscent of the yellow yielded from the green buckthorn drupes and in another ripe drupe recipe discussed here.

Buckthorn sap green Experiment 2, 2016

Merrifield 420 with variables

Iris Green 2016

Last year for my pigment experiments I used aluminum sulfate from a dye company thinking that was the right kind of alum.  In 2016 I made Iris green clothlets with the medievally recommended alum, Rock Alum, which I learned is aluminum potassium sulfate or potassium aluminum sulfate, KAl(SO₄)₂·12H₂O.

Iris Green Clothlets 2016 from De Arte Illuminandi

 Click "read more" below to find out how!

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.

Buckthorn 2016

It's nearly the 'vintage season' again and that means Buckthorn berry recipes!

Sap Green Buckthorn clothlets 2016

 

Rock Alum

This is my silly "rock alum" saga. 

The bottom line is that alum in medieval paint recipes is Potassium Aluminum Sulfate KAl₃(SO₄)₂(OH)_6.  

Read on for how I learned this.