One of the questions I’m often asked of my job as Conservator of Paintings is why don’t I retouch with the same pigments the artist used?
There are a number of answers to this but basically, sometimes I do use the same pigment and sometimes I don’t.
An example of where I’m likely to use the same pigments are the earth colours – raw/burnt umber, raw/burnt sienna, yellow ochre etc.
An example – where I do not use the same pigment as the artist is where they have used Lead White. Lead white is found in just about every painting (and household paint!) up until the late 20th century when H&S kicked in. It is fantastic as a paint – it handles well and is extremely durable but, the overriding nature of its toxicity means it is not a viable material for anyone to use if they want to live a healthy, long life. (Titanium white is the 20thC modern alternative).
Over the years I’ve used pigments in my work both as the colour for making the paint* to retouch losses in paintings, and in analysis to understand the original materials artists used.
Let’s begin though, with a brief history of Medieval and Renaissance Pigments.
The Renaissance period bridged the gap between the Middle Ages and the Age of Enlightenment, so roughly 1300-1600. It represents a great theoretical and scientific revolution in Europe.
You would think that such a burgeoning of science and theory and wealth and expansion would affect every aspect of the arts – which it did in one major way and that was oil paint. We’re not talking about that here though, because although the way artists painted did change quite radically with the ‘invention’ of oil painting, the major and most costly component of any paint both then and now is the pigment.
Pigments continued to be manufactured in much the same way as they’d aways been. Artists prepared the extensive range of colours available to them in the manner they always had since antiquity – they got the apprentices to do it. Lumps of raw pigment were washed, cooked, ground, graded, weighed and stored. Apprentices made paint by mixing pigments with egg, wax, mastic, resins and many other mediums – ultimately oil – and laid them ready to use, on the palettes of their masters. (All master artists had once been apprentices so they knew the score).
Increased maritime trading* delivered pigments to an increasingly demanding market, Church and Kings were big business. Artists used the colours in the same old way prescribed over centuries until the Renaissance. The Renaissance caused a shift, driving out the old fashioned, medieval preference for bright, pure, emblematic colours. Artists began mixing.
Using the same range of colours but mixing them allowed for subtlety and more naturalistic effects. This was really because with an oil medium they could do that which they couldn’t with all the other mediums to date, that is mix colours as they worked, paint bigger and for extended periods of time, working up paint layers instead of being limited to paint mediums drying quickly in small sections.
Oil took a long time to dry allowing artists to literally mix paint, paint over larger areas and even mixing colours on the canvas or panel or whatever support over longer periods of time.
Things got ‘realistic’ and quite often fantastical, which was new and really quite amazing and everyone wanted their portraits painted. Nothing like this would happen again for about 400 years when Picasso popped up – but that’s another medium along with some really amazing pigments and another blog.
Now where were we…….
Ah, yes, technical treatises of the Renaissance such as Lomazzo (Gian Paolo Lomazzo, 1538-1592 Italian painter & writer on art theory and practice – self portrait below) set out comprehensive instructions for the mixing of colours. It was complicated because as artists began to mix colours they had to do it themselves and became more aware of the issues of incompatibility of certain pigments in certain mediums.
Some pigments mix together less well in one medium than another. For example a pigment which is ideal for use in oil may well have serious disadvantages if used in fresco techniques e.g lamp black very difficult to use in waterbased paints. Some pigments if mixed or placed in close juxtaposition will react chemically causing discolouration e.g the blackening of lead white if mixed with sulphur based pigments such as vermilion/cinnabar.
Renaissance artists weren’t so bothered about the stability and permanence of their pigments but more with the visual effects of their painting. However there were a few circumstances where they had to pay close attention as certain combinations of pigments were to be avoided because the negative effects (examples above) happened quite quickly; artists had to pay attention as clients certainly did not want paintings deteriorating before their very eyes.
Technical treatise were a godsend to the artist with a deadline.
By the middle of the 16th century most artists studios weren’t using apprentices to prepare the pigments but sending them out to buy ready prepared pigments from the apothecary – who was no doubt reading Lomazzo too.
Painting got faster, bigger and really dramatic over the next few hundred years.
* & **
* Paint is, very simply, two materials mixed together – a pigment with a medium
(nouns:- medium; vehicle; carrier; binder – ‘s all the same).
In oil painting the medium would be a drying oil such as linseed, poppy or walnut.
In watercolour the medium is gum arabic; in acrylics the medium is…. acrylic etc.
Pigment + medium = Paint
In addition a diluent would be required to enable the paint to continue to flow as it is worked – turpentine for oils, water for watercolours and acrylics etc.
** One of the reasons Venice was such a seismic art/artist hot spot during the Renaissance was due to its geographic position – being the terminal for overland silk routes as well as prosperous maritime trading. Everything landed first in Venice.
The rise of Maritime nations such as the Netherlands inevitably witnessed a decline in importance of Venice as a northern renaissance grew with fortunes of maritime trade and the merchant classes who decided they wanted a bit of the painting action.
Next up:- Pigments of the 18th-20th Centuries; the rise of Modern Synthetic Chemistry