The manuscript I used as my inspiration piece is a page from the Book of Hours of Francesco Borromeo made in Milan, Italy sometime before May of 1474. The book was small, 93 x 70 mm or approximately 3.7 x 2.8 inches. The illumination was done by Ambrogio de Predis. Ambrogio began his career as an illuminator for two books of hours and then changed to painting miniatures and panels, sometimes in coordination with Leonardo da Vinci. I adapted the design of the illumination to be used as a scroll for a Flower of the Outlands award, recipient to be determined at a later time. I wanted the scroll to be of a size that calligraphy could be added so I increased the size of the illumination. I used parchment, as was used in the illumination, handmade gesso, shell gold, and pigments.
Cennini sets out the process that should be followed when illuminating:
If you want to do illuminating, you must start by drawing the figures, foliage ornaments, letters, or whatever you want, with a light lead on parchment, that is, in books; then you must crisp up your drawing carefully with a pen. Then you will need to have some of a color, or rather, a gesso, which is called size.
Making the Gesso
Many period recipes exist for gesso for gilding. These recipes have three things in common: a finely ground calcium carbonate for body, a colorant, and something sticky. The calcium carbonate takes many forms. Some recipes call for gesso sottile, some gypsum, and others white chalk. In theory, since all of these are calcium carbonate, if ground finely enough, you could substitute egg shell or seashell.
The second element of gesso, the colorant, is most often Armenian bole. Armenian bole is a red clay. Some recipes call for a combination of minium (red/orange lead) and ceruse (white lead) which they call blanchet. Many recipes include white lead, probably for malleability, the ability to deform without breaking. Saffron was also used as an optional colorant in one recipe.
The final element of gilding gesso, the glue, varies greatly. Often a combination of a few sticky substances was used. Egg glair was often used, sometimes in combination with sugar. Egg glair might also be applied to the gesso just before the gold is applied or only in the final layer of gesso. Honey was also used. Glues made from a variety of materials were used including stag horn, parchment, white leather, and bull-skin. Some recipes mention glue, but not what the glue was made of. Two gums were mentioned: gum arabic and gum ammoniac.
The period instructions differ in when burnishing should occur. Some recipes call for the gesso to be burnished between applying layers, some after the gesso is fully dry, and some after the gold leaf has been laid.
I tried to use an adapted version of a period lead free gesso. The recipe can be found in Merrifield's Medieval and Renaissance Treatises on the Art of Painting in the Manuscripts of Jehan le Begue Recipe 291, pages 258-266. This recipe is meant to be used on parchment, paper, linen cloth, cloth, and wood panels.
My test trial went well. The recipe calls for 4 parts white chalk, one part Armenian bole (a red clay), and then some hide glue. The chalk I used was 3 micron extra-fine chalk from Natural Pigments. I used some hide glue I got from a friend of mine. I had to add hot water to the hide glue and keep the glue warm to until used. After the chalk and bole were thoroghly mixed using a muller, I added a couple of drops of hide glue with quite a bit of water and mixed it with a palette knife. I applied 3 layers of the chalk/bole/hide glue gesso, burnished, and then one layer of gesso with egg glair. Even after trying to moisten the gesso with my breath, the gold would not stick to the gesso or an area of just egg glair or egg glair with a little water.
My one tweak was to use garlic glair (garlic juice) on the last layer of gesso in place of the egg glair. I tried a stripe of just garlic glair as well. I didn't wait long after the garlic glair to apply the gold. The gold stuck quickly and easily. After the gesso was dry (a minute or so) I burnished the gold to achieve a nice shine.
Unfortunately, I found that the gesso kept flaking off in areas and had to scrape off the original gesso and use another.
My final project used the first gesso I had made. I wanted to make a gesso that did not include white lead since I have small children and cats who wander through my work area. I was searching for a recipe that had been proven to work and found one used by Berend Van Der Eych, OL that uses all period ingredients. The recipe is as follows:
- 10 parts chalk, add water
- 3 parts fish glue
- Enough Armenian bole to make flesh colored
- 2 parts sugar
- Few drops each: egg glair, garlic glair, and gum arabic
Each part of the recipe I used was used in either raised or flat gilding or period gesso. I had each of these ingredients at hand. The other period lead free recipes all call for something that I do not currently have such as parchment or leather glue or stag’s horn glue, which are things that I would like to try in the future, but time prohibits me from creating at this time. I had made egg glair and garlic glair in flat gilding experiments. Fish glue I have also used to make paintbrushes. Chalk and gum arabic can also be used to make lake pigments and paint respectively. I have used this gesso several times on projects and generally have good results in that gold leaf sticks well in the dry climate of Colorado. I have seen some cracking, which may be due to having added too much fish glue.
Making the Shell Gold
I found four recipes in period manuscripts regarding the preparation of shell gold. Two recipes instruct the reader to grind the gold with salt, two without salt. One of the recipes that calls for grinding the gold with salt also includes a little sulphur. This recipe also seems to call for gold filings as opposed to gold leaf. Using salt to grind the gold is used in another recipe that calls for gold leaf. The salt is probably used as a grit to help grind the gold. Most recipes call for using gum arabic to help the gold stick to the page. The one outlier calls for egg glair and urine as the glue that binds the gold to the page.
To make my shell gold, I dipped my finger in a little liquid gum arabic and picked up a leaf of gold. I rubbed the gold around a glass dish for several minutes until the gold was finely ground, before picking up another gold leaf and repeating the process. I washed the gold by adding some water and stirring the gold water and then letting the gold settle. I then carefully poured off the clear water and repeated the washing process a few more times. When the gold was thoroughly washed, I added enough water to help move the gold and poured the gold into a seashell and allowed it to dry. Before using the shell gold, I added a little gum arabic and enough water to make a paint. I found that if I added too much gum arabic the shell gold would look too dark, and would not sparkle as much as I wanted. To remove any excess gum arabic, I essentially washed a little gum arabic away by adding some water, stirring the gold water, allowing it to settle and then pouring off the water like I did after grinding the gold leaf.
In this illumination I used peach pit black, malachite, azurite, brazilwood, iris green, and storebought titanium white pigments. Titanium white was not a pigment used in the time period, but the period choice, lead white, is toxic and I live in a home with small children and animals and didn’t want to take any chances of contaminating my home by using a toxic pigment.
Peach Pit Black
Other sources of plant material include peach pits and almond shells. The Marciana Manuscript mentions that charred peach stones make a “perfect black.” Cennini refers to both burnt almond shells and peach stones as a “perfect black, and fine.” The Brussels Manuscript mentions not only peach stones, but also plum stones, and mentions that the fruit stones should be extinguished with vinegar to make a “most excellent black.”
Malachite is a copper carbonate and is generally light fast. During period, malachite was probably found in Hungarian copper mines. Cennini says that malachite is an artificial color produced from azurite. The confusion may come from the fact that malachite and azurite minerals may often be naturally found together and Cennini thought that the malachite was created from azurite. Cennini also cautions to take care to not grind it too much or it will “come out a dingy and ashy color.”
I tried making azurite and malachite pigments starting with mineral specimens. I started with a couple small pieces of azurite and a very large piece of malachite. With the large piece of malachite I first broke off a few small pieces by smashing it with a hammer. I then put the pieces of mineral in a plastic bag or two and beat them with a mallet until they were in very small pieces. I found that wrapping the plastic bags in a shop rag helped keep the bag from disintegrating when smashing the minerals. The azurite was much easier to crush than the malachite. I then took the crushed pieces and put them in the mortar and crushed them further with the pestle. I had heard from friends how hard it was to crush minerals to make pigments, but I was surprised how quickly the process went. I think that the heavy weight of the mallet I used and using a stainless steel mortar and pestle as opposed to marble helped to speed the process. I found several mentions of a bronze mortar being used in period, but haven’t found one for less than $100.
The type of mineral crystal was very important. The original malachite I used was very dense with no visible crystal and took a lot of work to crush. I bought a small piece of malachite with very small needle shaped crystals at a rock and mineral show and found it so very easy to crush. I probably could have just crushed it in the mortar and pestle without the mallet.
After the minerals were crushed I used the process of levigation to separate the finest particles by weight to use for pigment. To levigate the powder, I added water to the powder in a small covered container and shook it. The coarsest particles immediately settled. I then poured off the water into another container. The finer particles suspended in the water slowly settled to the bottom. When the fine particles were completely settled and the water above it was mostly clear I poured off the water and allowed the pigment to dry.
Azurite is a carbonate of copper. A publication of the National Gallery of Art claims that azurite was the most important blue pigment in the Middle Ages and Renaissance. Azurite in medieval treatises is also referred to as azzuro della magna, azzuro todesco, azzuro spagnuolo, azzuro de Anglia, azzuro de Lombardia, lazurstein, and citramarium. The pigment is very lightfast, but can darken when exposed to sulphur fumes or turn green like malachite. Azurite was mostly mined in Hungary, but may have also been available from France and Sardinia. Merrifield states that when used as a pigment azurite and ultramarine are very difficult to distiguish by looking at them. Because of the difficulty of distinguishing azurite from ultramarine without chemical tests and because I had already made azurite pigment and paint, I used azurite in my illumination. The azurite pigment I used was made with the same process as I used in making my malachite pigment.
Several trees are known by the name brazilwood and produce a reddish dye. Caesalpina sappan may be the species that was used in period and is found in tropical Asia. The species I was able to find was Haematoxylon braziletto which is a New World species.
De Arte Illuminandi describes the process as such:
Take some of the best brazil wood . . . and with a knife or a piece of glass scrape off as much of this wood as you want. And put it into a lye made from the wood of vines or oaks (and if the lye is old it is better). And put this into a glazed dish which will stand the heat; and have the lye cover this brazil, so that whatever part of it is extractable may be thoroughly extracted by this lye. And let it stand in this lye for a night or a day to soften. Then put it on the fire, and heat it to the boiling point, but do not let it boil; and stir it often with a stick. Then take account of how much scraped brazil there was, and take the same quantity of very nice white marble very thoroughly worked up on the porphyry to an impalpable powder, or scraped with a knife, and as much sugar alum or rock alum as there is of the brazil. And grinding them thoroughly, mix them gradually in this dish, always stirring it with a stick, until the froth which it makes subsides, and it is well colored. And then it is strained through a clean linen or hempen cloth into a glazed or unglazed porringer. And know that some say that the lye, after it is well colored, should be strained through the cloth into a glazed dish; and after getting it fairly hot, they put in the alum and marble. And it will take up the color immediately; and the water will separate almost clear above it, and you pour it off carefully. And this is better.
I used the general process for making a lake pigment with powdered brazilwood and found that it produced a very pretty purpleish red pigment and paint.
Several manuscripts mention a green made from the flowers of irises which they also referred to as lilies. De Arte Illuminandi describes the process as follows:
Take these fresh flowers in the springtime when they are blooming, and pound them in a marble or bronze mortar; and squeeze the juice with a cloth into a glazed porringer. And in the juice soak other linen cloths, clean and soaked once or twice in a solution of rock alum and dried. And when the cloths are thoroughly saturated with the juice of the lilies in this way, let them dry in the shade, and keep them between the leaves of books.
The first pigment I attempted was iris green. I obtained a large amount of iris flowers from my local grocery store in the discounted flower section. Since I did not have time to work with them immediately I put them in the freezer. When ready to extract the pigment I took the blossoms out of the freezer. When using fresh blossoms, it is necessary to crush the blossoms to extract the color, but freezing punctures the cell walls of the flowers and I was able to put the blossoms into cheesecloth and simply squeeze the color out of the blossoms. At this point I put the blue liquid in a bowl and added alum to try to get the liquid to change color from blue to green. The color change never occurred so I used more alum. I was never able to get a color change. I then soaked cloths in the liquid and dried them outside. Unfortunately I forgot the cloths outside and rain removed the blue color. I look forward to trying this pigment again.
I tried again recently. I used fresh iris blossoms that I again found in the discount area of my local grocery store. I picked off any bits that were not blue including the outside petals that had some green on them and the yellow stamens. I then crushed the blossoms in a mortar, put the crushed blossoms in cheesecloth, and then squeezed the juice out of them. I had prepared a clothlet ahead of time by soaking it several times in alum water and drying it between treatments. I used some old flour sack towel as a clothlet as opposed to good linen because that’s what I had on hand and what was cheap. I then soaked the clothlet in the iris juice and let it dry.
The clothlet did not turn as green as I had thought it would. It did turn from purple to a dark greenish blue. I took a bit of the clothlet and put it into a seashell with a little gum arabic water to make a paint. I tried adding a little more alum to the paint water to see if I had not used enough alum when treating the clothlet, but more alum did not make the paint significantly greener. When applied to paper, the paint turned darker as it dried. The paint is much greener than the clothlet. The recipe also says that orpiment can be added to the paint to make it greener. I would classify this attempt as a success. I was not able to use the species of iris that would have been available. I do have some Iris germanica growing in my garden that I hope I can collect this summer and hopefully try again to see if the clothlet turns more green with an appropriate iris species.
In addition to the clothlet recipe, I found several more traditional pigment recipes. Three of the recipes were found in the Paduan Manuscript contained in the Merrifield book. The first relies upon the calcium in the seashell that it is dried in to achieve a color change.
Take the purple lilies, that is, the flowers, and of these the petals only are to be used, and pound them until they are well bruised, and leave them until they begin to ferment; then take burnt roche alum at discretion, grind and incorporate it well with the lilies, leave them on the grindstone for 5 or 6 hours; then prepare the shells, and take a worn linen rag, put the lilies into it, and press the juice dexterously into the shells or vases; then dry the color in the shade, and you will have a beautiful green; and if you wish to make the colour lighter, add to it a little quicklime at discretion.
I followed the recipe as closely as I could. I picked all of the blue parts of the flowers and put them into a covered container and allowed them to sit for a day or two. I then added a little alum to the blossoms and crushed the blossoms and allowed them to sit for 5 hours. I found that by allowing the blossoms to ferment made them softer and easier to crush in the mortar. I placed the blossoms into a piece of flour sack towel and squeezed the juice out. The color at this point was a dark blue. As soon as I placed the juice into a seashell to dry it began to change to dark green as it dried. To make paint I added a small amount of gum arabic water to the shell. The color was a beautiful dark green.
 Cennini, Pg. 100.
 Manuscripts of Jehan Le Begue, Pg. 258-266.
 Van Der Eych, Berend, Medieval Illumination Gold Leaf. https://www.youtube.com/watch?v=0pnh7E1oWvo. Last visited March 13, 2019.
 Manuscripts of Jehan Le Begue, Pg. 304.
 Manuscripts of Jehan Le Begue, Pg. 320.
 Manuscripts of Jehan Le Begue, Pg. 240.
 Marciana Manuscript, Pg. 610.
 Cennini, Pg. 22.
 Brussels Manuscript, Pg. 820.
 Roy, Volume 2, pg. 183, 187.
 Roy, Volume 2, pg. 184.
 Cennini 31.
 Cennini 31.
 Cennini 25.
 Roy, Volume 2, pg. 23.
 Roy, Volume 2, pg. 25.
 Merrifield pg. cxcvi.
 Roy, Volume 2, pg. 27.
 Roy, Volume 2, pg. 25.
 Merrifield pg. cxcix.
 De Arte Illuminandi 8.
 De Arte Illuminandi 6-7.
 Merrifield at 687.
Ambrogio de Predis, Wikipedia. https://en.wikipedia.org/wiki/Giovanni_Ambrogio_de_Predis. Last visited March 10, 2019.
Book of Hours of Francesco Borromeo. https://guenther-rarebooks.com/artworks/9393/. Last visited on March 10, 2019.
Lucas, Angela. Raised Gesso Gilding Techniques Based Upon Contemporary and Historical Methods. http://uregina.ca/lucasa/Raised%20Gesso%20Gilding%20Techniques.pdf. Last visited March 13, 2019.
Van Der Eych, Berend, Medieval Illumination Gold Leaf. https://www.youtube.com/watch?v=0pnh7E1oWvo. Last visited March 13, 2019.
A Short Section on Illuminating; First, How To Gild On Parchment
If you want to do illuminating, you must start by drawing the figures, foliage ornaments, letters, or whatever you want, with a light lead on parchment, that is, in books; then you must crisp up your drawing carefully with a pen. Then you will need to have some of a color, or rather, a gesso, which is called size, and is made as follows; take a little gesso sottile, and a small amount of white lead, less than a third as much of the gesso; then take a little sugar candy, less than the white lead. Grind these things very fine with clear water. Then scrape it up; and let it dry without sun. When you want to use some for gilding, take a little of it, as much as you need; and temper it with white of egg, well beaten as I taught you before. And temper this mixture with it. Let it dry. Then take your gold; and you may lay it either with breathing or without breathing. And as you lay the gold on it, take your crook and burnishing stone, and burnish it at once; and put a solid little panel of good wood, nicely smoothed, under the parchment; and do the burnishing on that. And know that with this size you can write letters with a quill, <and do> grounds, or whatever you please; for it is most perfect. And before you gild it, see whether you need to scrape it, or level it, or clean it up at all, with a knife point; because your little brush sometimes lays more in one place than in another. Always look out for this.
Another Kind of Size; For Grounds Only
If you want another kind of size- but it is not so perfect, though it is good for gilding a ground, but not for writing – take gesso sottile, and the third, white lead, and the fourth, Armenian bole, and a little sugar. Grind all these things very fine with white of egg. Then lay it in as usual. Let it dry. Then scrape and clean up your “gesso” with the point of a penknife. Put the little panel, or a good flat stone, under the parchment, and burnish it. And if, by chance, it does not take a good burnish, wet the gesso when you are gilding, with clear water on a little minever brush; and when it is dry, burnish it.
Del Arte Illuminandi
14. Size for Laying Gold
Size for laying gold on parchment is made in many ways. But I shall put down a certain rule for it which is both good and tested. So take as much as you want of the calcined and prepared gesso which the painters use for gilding panels, that is, the gesso sottile, and a quarter of that amount of the best Armenian bole; and work it up to the utmost fineness with clear water on the porphyry slab. Then let it dry on this slab, and take whatever part of it which you want, putting the rest aside, and grind it with stag’s horn glue or parchment size. And put in as much honey as you think necessary to give it a sweet taste; and in this it behooves you to be careful, so as not to put in either too much or too little, but, according to the amount of the material, so much that, if you put a little of the compound into your mouth, it just barely tastes sweet. And you may figure that for one of the little dishes that painters use, twice what you can pick up with the handle of the brush will be enough; and if there were any less, the compound would be ruined. And after grinding thoroughly, put it into a glazed dish, and at once pour enough clear water on it to cover it, working carefully, without disturbing the material; and it will immediately be refined in such a way as not to make either bubbles or holes after it dries.
And when you want to use it, after a brief delay pour off the water which stands over it, without stirring the material at all. And always before you lay any size on the actual place where you have to work on the parchment, you should try it out on some similar parchment, to see whether it is properly tempered; and after it dries, put a little gold on it, and see whether it takes a good burnish. And know that, if there is too much of the tempera or of the honey in it, you correct it by putting plain soft water over it in the dish, without any stirring; and if it stands for some time, and the water is then poured off, still without stirring, the tempering will be improved. And, if it should need a stronger tempera, put in more of the size, that is, more of the solution of it, or more of the solution of honey, if that is needed, until the composition suits you. And since experience is worth more in all this than written documents, I am not taking any special pains to explain what I mean: - a word to the wise…!
15. How to use it.
You ought to know that after the letters, or leaves, or figures have been drawn on the parchment, the places where the gold is to be laid should be rubbed over with a scrap of stag’s horn or fish glue in this way. By moistening a scrap of this glue in your mouth, on an empty stomach or after digestion, until it has softened, and with that, constantly moistening that scrap of glue, coat the place where the gold is to be laid, so that the parchment gets made more manageable for taking the size. And some people even coat the whole drawing in this way with this glue, so as to make all the colors unite better; but this would only be necessary if the parchment were hairy or rough. And the parchment can een be wet down or coated, wherever the gold and colors are to be laid, with the size solution, sweetened with a little honey, and applied deftly with cotton, as required, or with a brush; and this is better. Then take this size, well tempered as has been said, and with a brush right for this purpose, put it on, quite wet at first. And when it is almost dry, put some once more over this size; and do this two or three times until it seems to be about right, and neither too thick nor too thin, but adequate. When the last coat is quite dry, scrape the surface carefully with a good and suitable knife, and clean it up with a hare’s foot. Then take some glair of eggs broken with a bristle brush or with a reed, split and adapted for that, as the painters do; and when all the white has been turned into froth pour over it enough plain water, either mixed with the best white wine, or a little lye, or plain, because any of these is good. And after a little while pour it out from the froth which it produces on top, and what remains will be good. Then take some of it, with a brush fit for this, and wet over this size with judgment and moderation, so that this size will take the gold or silver readily, as the painters do when they are laying gold on panels. And cut the gold with a knife upon parchment, as you know how to do, according to the number of places where gold has to be laid; and if necessary, you may force the leaf to stick to the size with a bit of cotton. And after a little while, when it is practically dry and can stand burnishing, you burnish it with a suitable tooth of a wolf or calf, or with a hematite stone as the painters do, on top of a panel of box or other wood, well polished and sound. And if the gold comes out imperfect anywhere with this glair carefully wet the place where the gold is imperfect, and lay the gold, pressing it down with cotton if need be. And after all the gold has been burnished, rub it lightly with a hare’s foot; and any excess which has not been removed by the foot, scrape off and even up with a good sharp knife. And after removing the excess, burnish it again, until it suits you perfectly. And so, with a stone of hematite or other tools made for this, one can rule or stamp the gold laid in this way, over the panel of box or other wood, etc. And do it will be finished.
And though there are many other ways of laying gold or silver on parchment, and the size can be made from many other things, still I have simply given that method, because it seems to me to be one of the best, and because that method is quite general among all illuminators.
Merrifield-Manuscripts of Jehan Le Begue
104. To lay burnished gold upon paper.
Take gesso sottile and grind it on a stone with water. Then let it dry, and when it is dry take some glue, not very strong, and mix with it, and add a little minium and ceruse—i.e. blanchet—and lay the gesso on the paper, and let it dry. Then scrape it, and lay over it Armenian bole well ground with white of egg, and when it is dry, lay gold upon it with white of egg, and burnish it in proper time.
190. How to lay gold on a wall, or on parchments.
If you wish to lay gold on a wall, or on paper, or on wood, or upon a block of marble, grind gypsum by itself separately. Then grind brown separately in the same manner, and take three parts gypsum and one of brown, and take glue made from parchment or leather, and distemper them together, mixing the said parts, and lay upon it [the object to be gilded] one coat of this mixture with a piant-brush, and then another; and so lay three or four coats. And when the last is dry, scrape it with a knife or other iron instrument fitted for the purpose, so that it may be very smooth; and then burnish it with a tooth or a stone, and lay over it, with the paint-brush, only one very thin coat of the gypsum, and let it dry. When it is dry, lay the gold upon that mordant, as you have been taught. Afterwards lay upon the gold a very fine cloth that has been two or three times warmed; or apply it as I do, not so warm, in order that the gold may be the better polished.
191. Also how to lay on gold.
Take gypsum and grind it well with water. Then take your glue which is made of bull-skin and mix with it a little white of egg, and distemper the gypsum. But when you wish to lay on the gold, cover the place with gypsum with a paint-brush, and let it dry. Do this three times. Then scrape it, that is may be smoth, and burnish it, and again lay another coat of the glue or mordant upon it, and then your gold upon that, and remove the dirt gently with cotton, and then let it dry. But if you wish to polish it, do so with hematite, or with a dog’s-tooth.
192. Also how to lay on gold. ***flat gilding***
Take basilium, newly distempered with white of egg, well whipped with a sponge or otherwise, and draw and paint with it whatever you like on vellum or on any other thing you wish to gild, and immediately lay the gold upon it, and remove the dirt with cotton, scarcely touching it, and leave ti to dry for half a day or a whole day if you like. Then take a dog’s tooth, and begin to burnish at first gently, les you should spoil it all, and then harder, and afterwards so hard that your forehead is wet with perspiration. And if you wish to lay gold on parchment made of sheep’s skin, add a little plum-tree-gum, otherwise gum arabic, which is excellent for working on any kind of parchment, namely, from calf-skin, sheep-skin, and goat-skin, as we shall declare in the following [recipe]. And either kind of gum must be distempered as follows:
193. The mode of tempering the gums for laying gold
Take whichever of these gums you like, and tie it up in a very clean linen cloth, and put it in a glass vase, and let it lie in water for a whole day and night, although indeed, if you want to make haste, you may stir up the water with your finger. Then draw whatever you like on the parchment and ay the gold on it as before mentioned.
Of the precautions required in gilding.
But take notice that you ought to work in gold and colours in a damp place on account of the hot weather, which, as it is often injurious in burnishing gold, both to the colours on which the gold is laid and in [the operation] of gilding, if the work is done on parchment that is too dry and not sufficiently moist; so also it is injurious when the weather is too dry and arid, or too damp, while applying colour or gilding.
195. Also how to lay on gold.
Take gum arabic and distemper it as aforesaid. Then take gum ammoniac distempered with hot water over fire, and mix it with the gum arabic, and stir it with your finger, and put it in the sun, that it may be well mixed and liquefied. Next take gypsum, and distemper it with white of egg, and mix it with gum ammoniac and gum arabic. And when you wish to gild leather or purple cloth, or linen or silk cloths, stir it up altogether, and draw beasts and birds and flowers upon them with a very sharp stick, and let them dry. Then take the gold, and blow gently on the flowers, and lay on the gold directly, and press it down with a burnishing tooth or stone, and burnish it as before.
XLII (278) How to gild on parchment.
Take gypsum and white of Apulia, ad carminium, that is to say, cinnabar, namely, one third part of gypsum, and two equal parts of white and of carminium. Mix them well, and grind them on a marble slab, and add to them only a little thin glue; and with this mordant you may lay on gold wherever you like, and you may keep it a long time.
291. For laying gold in different ways upon various articles so that it may be burnished, and the cautions to be observed concerning this in painting.
Lay laying gold on parchment, paper, linen cloth, sindone, and on primed wooden panels, which gold may be burnished, that is polished. Take the white gersa, which is otherwise called white chalk, which is found in abundance at Bologna and at Paris; and a little Armenian bole, in quantity about one-fourth of the chalk, or a little crocus, which is commonly called saffron. This Armenian bole and this saffron are not added because they cannot be omitted without great inconvenience by any one who wishes to do so, but merely that the colour may not be white, but yellowish or reddish; and not for any other reason than this, namely, that when it is laid upon the paper, it may differ from the whiteness of the paper, and thus the things which are made of it are better seen than they would be if the colour of it was white like that paper which is called parchment. Grind all these things very fine upon a hard stone, well polished, and broad, with another stone to be held in the hand, polished in the same manner with clear water from a well or spring, and let the mixture or color be made, which is in French called assiete, which you may afterwards if you like, before it is quite dry, but after it is set, distemper with glue water, made with glue from cuttings of the white leather of which gloves are made. Clippings of parchment also are good for this purpose, but the cuttings of the white leather make the glue stronger. Lastly, let the size, or sized water, be warm; I say warm lest it may be conglutinated, because if the size is as it ought to be, when it is cold it will be congealed like jelly for galantine [brawn] not very hard, and this on accord of the glue which is made to enter into the water by decoction of the cuttings of leather or of parchment in that water, which is congealed by cold. And therefore summer weather is very convenient for this, both because it does not allow the colour to congeal or chill, and because it makes the colour dry quickly when it is laid on. And with this warm size, you must, as has been said before, distemper the said powdered color or tempering for laying on gold, so that is may be soft and liquid like good ink for writing, or as it may seem convenient. Having done this, write, draw, and fill in or paint whatever you wish with it, and rather with a paintbrush than a pen, because if it were done with a pen, and were to become chilled in the pen, it would flow so well as with a paintbrush; moreover, when using a paintbrush, the colour may be held in the hand, which by its warmth or heat, will not allow it to congeal; this however, can also be done well with a pen, but a paintbrush is much more convenient. And, in painting with a pen, as well as with a paintbrush, it is a good thing to keep the colour over a slow fire of charcoal, at such a warmth, that it may not congeal, but may remain liquid. Afterwards let those things dry which you have drawn and painted, and when they are dry burnish them, that is, polish or smooth them gently with a tooth of a horse or boar, or with a polished hard stone fitted for this purpose, in order that all the roughness may be softened down, particularly in those places in which you have put this size or colour. Then grind some more, and again paint over and draw upon those same places, with this colour, as before, and afterwards let it dry, and then polish and burnish it as before. Afterwards go over and repaint those places which you did before, with the same mordant or colour, but let this third and last coat of colour be tempered with white of egg whipped or beaten, so as to be liquid and without any particles conglutinated or adhering together; because this white of egg makes a size or vehicle sufficiently strong to hold the gold for burnishing and to resist the shaking and violence of the friction and rubbing the burnisher over the gold. Then before the colour on the places in which you put it, is dry apply the gold quickly, and allow it to dry, and afterwards burnish all these things with the same tooth, stone, or other instrument, you used before as above mentioned, but first pressing lightly and afterwards harder still, particularly on parchment, paper, and panels; but on cloth and sindone not pressing so hard, and taking great care lest what has been done should crumple up and be broken, and so those things which you drew and painted, and upon which you laid the gold, will remain clean and polished; and the forms and lines made with this colour will remain brightly gilt.
But it must be observed, that on parchment, paper, and panels it is sufficient for the said colour to be put on once only, tempered with size, and afterwards, for the last coat, with white of egg, provided that it is laid on well the first time with tempered with size. But on cloth or sindone it is more necessary that this colour should be laid on twice, while tempered with size, before it is put on for the last coat tempered with white of egg. And this is because sindone and cloth, owing to their porosity, are too absorbent, flowing, flexible, and unstable, and therefore soak up the colour, so that there does not remain a good and firm substance of colour upon the cloth or sindone, unless as useful experience tells us, it is laid on several times. And this flexibility and instability of the cloth or sindone can be corrected and reduced to firmness in no other way than by the tenacity and viscosity of the flue laid over them for this purpose. And therefore care must be taken as regards the situation, because windy weather is a hindrance, unless the gilder is in a closed place; and if the air is too dry, the colour does not take the gold well; and, if it is too wet, the colour cannot hold the gold under the burnisher. Care must also be taken that the linen or sindone which is chosen for this purpose be well woven and strong, and as close in the texture as possible. The colour itself ought not to be applied too thick or too cold, lest by the curve made in folding them the colour should scale off and fall away along with the gold; particularly under the stroke of the burnisher, while the gold upon it, as has been already mentioned, is being burnished; and so your labour should be thrown away. And even supposing that the cloth, sindone, paper, or parchment, on which gold has been laid in the manner hereinbefore described, should be folded into slight creases, as frequently happens spontaneously and by chance, and unless they are folded and rubbed together, cracking the priming by violent and voluntary force, the gold will not fall off or start from the places in which it has been laid.
Shell Gold Recipes
How to Grind Gold and Silver for Use as Colors
If you want to work with gold on panel, or on parchment, or on wall, or anywhere else, but not all solid like a gold ground; or if you want to make a tree look like one of the trees of Paradise, take a number of leaves of fine gold according to the work which you want to do, or to write, with it; say ten or twenty leaves. Put them on your porphyry slab, and work this gold up well with some well beatedn white of egg; and then put it into a little glazed dish. Put in enough tempera to make it flow from the quill or the brush; and you may do any work you want to with it. You may likewise grind it with gum arabic, for use on parchment. And if you are doing leaves of trees, mix with this gold a little very finely ground green, for the dark leaves. And in this way, by mixing it with other colors, you may make shot effects to suit yourself.
Manuscripts of Jehan Le Begue
XLIII. (279) How to write with gold.
Take a glass vial and fill it with urine, and let it rest until it appears clear. Then take the white of an egg well whipped and divide it into two parts, and mix it with the urine, and stir them both together, and put them into a horn with gold dissolved, that is ground, and then washed. You may write with this gold as with any other colour.
320. To write with gold and silver.
Take leaf gold, grind it with salt on the marble, leave it for a long time in water, stir it and let it settle. Then pour off the water to remove the salt, and the gold will remain at the bottom. Distemper it with gum for writing, and the letters you make will be dark; but when they are dry, polish them with a tooth and they will be of a beautiful yellow shining gold colour. If you choose you may write with silver in the same manner.
322. A recipe for grinding gold.
Take some very fine and pure gold filings, grind them in a mortar such as is used by apothecaries, which is made of three parts copper and one part of tin or lead; such are their mortars. But previous to this, your gold filings should be well washed in a basin or in a shell with a pencil. Then grind all your gold in the above mentioned mortar, so that when finished it shall be left clear. And in the manner you may grind copper, silver, brass, pewter, and all other metals; but take care that the gold does not burn, as it would be necessary to regrind it. When the operation is finished, remove the water and impurities, let the gold settle, then place it over the coals with water and warm, and stir it.
323. To grind gold, and how it should be softened.
Take well-filed gold, grind it well on a porphyry slab with the parts of sal gem [rock salt], a little yellow Sulphur in a glass vessel, changing it frequently from one vessel to another until it is well washed and purified. Then put it into a horn, and when you wish to use it, distemper it with gum arabic, which must be put into a glass vessel with water and exposed to the rays of the sun, until it is dissolved. When it is dissolved put it into a saucer with as much silver as water, and let it be tepid when you write with it, which you must do the same day before the fire. When dry, let it be burnished with a tooth.
Brussels Manuscript- Merrifield
First, ground Gold.
To grind fine gold, so that one may paint or write with it with the pencil, you must take gold leaf with 4 drops of honey, mix the whole together, and put it in a small glass vessel; when wanted for use, it must be distempered with gum-water.