PATINA COLOURING
What is it & Why such a rap around it?
By reading an article related to patinas, I came across a fascinating description of the patina phenomenon which impacted me for its very profound spiritual value. It appears that the formation of patina in metals is due to the fact that all metals have the tendency to go back to their natural state, that is, “to return to their original mineral form…”
It seems we borrowed the word to the Latin 'patÄna' indicating a shallow plate. As this dishes travelled through time, their surfaces went through a process of spontaneous and natural oxidation. By extension, this very word came to refer to any fading, darkening or sign of age on about everything, metal, wood, and stones, ceramic, glass, etc,…
Copper and coppers alloys such as bronze start this inevitable process of oxidation immediately on exposure to the air (its acidity, moisture, etc…), the elements, not to forget even the simple touch of your fingers. But the process is so gradual that it takes a very long time to get a 'beautiful' patina (not just some dirty-effect). Could it be that this is why we came to value patina's so much? Some of my patina's illustrated below:
Natural patina (Aquired)
Called 'Vert de gris' in French, it forms naturally and intensifies with time. The more time the thicker the layer… the more moisture in the air, the faster it grows. The idea of having a sculpture only patinated by nature is very attractive, but my customers and I would have to accept we would be long dead before we can witness a 'beautiful' patina on my statues. Fact is that, in its early stage of oxidation, the tonalities of the patina (grey-ish, green-ish, brown-ish) are tern and lifeless resulting in a sculpture merely looking neglected, we could even say, dirty.
Artificial patina (Applied)
By using chemical solutions reacting with the surface of the bronze, it is possible to control colour, transparency and timing (heat accelerates the process) of the patina. Applying a patina by chemical means has been used as a decorative technique by many different cultures for thousands of years. However, it seems that this method took a all different meaning during the Renaissance when it was primarily used as a means of conferring the appearance of antiquity on a sculpture. Patina… Not out of consideration for beauty 'per se' but to trick the lover of antiques? Hummm… In the late nineteenth century, the art lover came to appreciate a greater variety in colors and finish of surfaces (skin of the bronze or 'satinatura). But it is during the twentieth century that the patina really became 'famous' per se. Trend commanded! The art lover and the artist move away from traditional colorations (you surely heard of the 'Florentine brown') and became obsessed with colour and colours on the surface of bronze. It is now possible to colour bronze chemically in a huge range of tones but the purists make a precise distinction between patinated bronze and painted bronze… Some patina colors (white for ex.) are indeed achieved by adding pigments to the chemical which is the only substance which actually reacts with the metal. The professionals are a little reluctant to 'paint' bronze also because pigments being water-soluble, they tend not to do very well when exposed outdoors.The chemical I used so far are: Liver of sulfur > brown; ammonium sulfide > blue-black; cupric nitrate > blue-green; liver of sulfur > brown-black; ferric nitrate > yellow-brown. Unofficial but very efficient is urine! I never used it but I witnessed a dog creating a perfect green patina over some bronze he found on the ground of the foundry… Would this method find some prestige if you were told that, the French sculptor August Rodin is said to have instructed assistants to urinate over bronzes stored in the outside yard of his studio?
Cold or warm patinas?
Since I discovered the 'cold' technique, I stopped 'burning' the skin of my bronzes and gave more time to the patina procedure. By heating the bronze (use of torch being the most common method but placing the piece in an oven is another efficient way to warm up the metal) the patina can be done in a few minutes. Almost all foundries use rapid techniques because as it allows the customer to be present to the process and take some 'hot' photos! However, I came to appreciate the excellence of execution and the outstanding quality of cold patinas. Working 'slow' allows a very high level of control of the color, its finesse and transparency. The main quality involved when applying a cold patina is patience, more patience and some more patience. This is how I do it: a) I carefully brush the skin of my bronze with a metal brush (copper brushing on the finest items, steel brushing on more robust surfaces) in order to open the pores of the bronze-skin. b) I carefully clean my surfaces with fat dissolving detergents, rince abundantly and never touch my sculpture with bare fingers after that. Why? Because human skin, no matter how clean, always retains some traces of fat and other acidic elements. c) I prepare my chemical compound and apply a thin layer 'au tampon' (little soft rug I shape in the form of a tube) or 'au chiffon' (unshaped little rug) and or with a soft, very soft clean brush. I make sure I cover the all surfaces as evenly as possible. This might mean I track any possible 'pool' of chemical and carefully brush it away. d) Time for me to step away and let time do its job. e) Before I renew any application (between 2 and 3 times a day), I softly wash the piece with fresh and clean water. I can't predict how many applications I will need, I just stop when the colouring satisfies my eyes and the eyes of the customer. I can say that it took me almost 1 month to achieve a dense but very transparent and eventually just spectacular black patina on 'Le Tendre Secret'. Countless applications... For the piece titled 'Trust', I first made a perfect black which took me about 3 weeks but then I strongly resented such dark colouring for 'killing' the perception of the superb quality of the bronze and of many sculptural meaningful details. So, I brought the statue back to a no-patina state, started all over the patina process and found that 'Trust' was perfect with only 1 single application!
Finishing touch
When satisfied with a patina, it is necessary to stop the oxidation process, which would otherwise continue, by washing the piece with clean water. But that's not all...Patinating the bronze does not make the metal less porous, that is to say, the colouring can remain unstable, especially when exposed outdoors. In order to gain (not grant though) stability, I apply a layer of wax cream onto the surface. I let the wax rest for a good 24 hours and then, just like I would do with a pair of leather shoes, I use a soft textile to eliminate any possible thick trace of wax. I often use coloured wax cream to intensify or even slightly modify the colouring of the bronze while I use neutral wax if I do not want the wax to interfere in any way with my previous result. I can also choose to use 'mat' or 'shining' wax, depending on the result I want for the piece. Anecdote: I recently received a photo a client made of a garden piece I created for him titled 'God Chasing You, Leda'. I was surprised but sincerely delighted to see how fast the patina had evolved from almost non existent light silvery tones to intense silver/blue. This rapidity, I attribute to the fact that he lives near the sea. The waxing of the surfaces did not prevent the air and the elements to change the patina but that the piece gained in beauty while maintaining its transparency (essential when the bronze is of exceptional quality). was a bonus I did not expect!
My patina 'colours'
Let's say it immediately: although I have immense pleasure in creating the most beautiful, thin and transparent patinas for my statues, I would gladly refrain from colouring the bronze in any way. One requirement: the finished bronze quality must be exceptional, that is, no need to 'hide' anything! Now, why do I patinate? Besides helping the alloy to be colour-stable, I also take into account the fact that a statue with absent-patina is almost impossible to maintain. The customer would have to commit to obey very precise maintenance rules, such as never touching the skin of the bronze with bare fingers. But even then, bronze being an alloy mostly made of copper that is to say, prone to inevitable oxidation, it would quickly turns into a dull grey-green and 'dirty' looking metal. Applying patinas is such a 'normal' procedure that very little people know which color bronze has. Let's see:
1) As I break the investment mould, I see a mat dark grey metal, with purple black patches and traces of plaster. This color range can be so very beautiful that I never miss taking photos of this moment. Some modern artists even consider the piece as finished once it reaches this stage.
2) After 'decochage' (water & sand blasting procedure) most traces of plaster disappear while the dark grey and purple black patches remain. This is also a very beautiful moment to photograph, especially when the bronze is still wet as some more purple and some gold are revealed.
3) At soon as a tool cuts or attack the bronze surface, a brilliant 'Or Jaune' (yellow gold) color appears. I find the color of the chiseled bronze to be most beautiful 'per se'.
4) Equally beautiful is the color of the bronze once I give it a sand blasting treatment (cleaning and opening every pore of the bronze skin). This procedure reveals a mysterious mat 'Or Rose' (pink gold) of amazing softness.
Renaissance brown
With the 'absent' and 'black' patina, the brown is my favorite… It is called 'Renaissance' (sometimes 'Florentine') because it was very popular in Italy during the 15th century and later. The Renaissance man was re-discovering Greek and Roman works of art, collecting originals and copying them with passion. A real fervor which gave the artists and artisans an opportunity to study and re-learn many techniques their 'renaissance' society had lost. The art of patination was one of them. The Renaissance brown works magnificently for interior pieces (great part of my collection) because some marvellous effects (rich variety of subtle brown tonalities) can be achieved. When applied artistically, it enhances the fine casting by truthfully revealing the 'satinatura' (skin of the metal) in its most subtle details. It is not a safe choice because a mediocre cast or negligent chiseling can't tolerate its merciless transparency. I consider this patina a declaration of excellence of execution!
Black but not Herculaneum black
The Herculaneum Black is a popularised green black patched color (which the romans probably never used) used by restorers who needed to satisfy the Bourbon's society and the aristocratic families of Naples, Italy, fervent collectors of antiques. In the 18th century, every aristocratic home had to have a collection of bronzes from Pompeii and Herculaneum. The demand was so high that quality suffered and this patina allowed the covering up of all imperfections. In fact, by levelling everything ou, the black&green patching makes the viewer 'blind' to possibly embarrassing flaws. And, it also aged quite beautifully by developing further natural green areas. But camouflage is not my thing and I never 'patch', also, I work at obtaining the purest and thinnest black I can possibly achieve. Applying a black-black patina is a beautiful technical challenge (especially when done cold) but is not an easy decision because black absorbs all light and needs to be displayed in a very bright surrounding if it wants to be 'seen'. It works very well when the statue offers mostly large plans (Le Tendre Secret, Esmeralda). I have had the experience of creating a spectacular black on several pieces (Euterpe, Trust) but could not sustain my initial choice… I kept resenting not giving a chance to the bronze to be better seen! This is how, in spite of working on my black for about a month for each piece, I decided to sand blast the entire statue and start over again… I was very satisfied when I applied the lightest brown on Trust and even refrained from applying any patina on Euterpe.
Pompeii Green
I mostly work with human figures and I could never find valid artistic reasons to turn them green (color of sickness!) but there was a period I did use to apply polychrome patina's when the figure was wearing a drapery. The drapery would be treated green while the proper skin of the statue would be treated brown. Examples are the early versions of Flora, L'enfant, Femme de Claude Monet, Hommage a Edgar Degas, etc… I then received the eye-opening comment from Peter Pappot, well established and renowned Art Dealer of Amsterdam who was successfully exhibiting my work in his Gallery of the Nieuwe Spiegelstraat, in Amsterdam. He felt I was victim of fashion and advised me to stay 'sober' and, since my work was appreciated for its classical nature, to sacrifice trend and remain 'classical'. He was so right… In galleries and art fairs, I would see a plethora of similar brown&green color effects. Indeed… 'fake-ness' there and a tendency to distract. I was determined to offer my customers a kind of sobriety which would allow them to experience the beauty of a good sculpture, the beauty of a great cast and the preciousness of a superb 'satinatura' (skin) so, unless I change my mind again, no more polychromy for me!
Magnificent...The absent patina!
Ideal when the piece is in a environment poor in light for bronze is itself a vibrant light giving point! Only the best cast and finish can afford to be left 'in the nude', as I call it. I can still 'play' with 2 colours: Or Rose for the fleshly sand blasted statue, Or Jaune, for the chiseled and brushed statue. To grant stability, I spray the bronze with a thin layer of transparent lack, mat for the Or Rose (Euterpe) and semi mat for the already brilliant Or Jaune.