Gold is yellow, right? Well not really: some golds are more yellow than others. The two icons of St Francis above are looking like one of those 'spot the difference' puzzles we used to get as children, but the chief difference - the colour of the gold leaf I used in each - is not at all obvious on the screen. When you go to buy a book of gold leaf - generally from an on-line supplier - the array of golds on offer is completely bewildering. Bog standard 'yellow' gold can be 24, 23 or 22 carat, extra thick, double thick or regular, and each differs slightly in its tone. Not enough difference to read on a computer screen perhaps, but very obvious if you accidentally mix them up on the same painting (yep, been there!). Then there's Italian gold, German ducate, moon gold, red gold, lemon gold, green gold, champagne gold, white gold - the computer screen doesn't give one a very good idea of the differences and sample books are very expensive. The different colours are determined by the quantity and type of alloy metals in the leaf - silver, copper, nickel etc. 24ct gold, being pure, is a rich yellow colour; 22ct tends to be slightly more silvery. Some gold leaf has more of a crinkly texture, which you may or may not like. The presence of copper in the mix makes the leaf appear pinker (one sees this reddier tone clearly in gold jewellery made in India, for example).
So how to choose? Well, anything below 22ct is likely to tarnish fairly quickly, so is best avoided for work that you want to last: that instantly eliminates quite a number of options offered by the goldbeater. 24ct gold is more malleable and does not tarnish at all, so is chosen for 'best work' and for anything that will be exposed to the outside air. It is softer and therefore show the joins between leaves less after burnishing. Using 'double' or 'extra thick' gold leaf may mean you can avoid double gilding, which is generally necessary in order to get a good finish with standard thickness leaf: it is more expensive than standard thickness, so you will have to calculate whether with luck and skill you will make a saving or end up having to double gild anyway! For work intended to stay indoors, so less exposed to atmospheric pollution, 22 ct is adequate and perhaps a little easier to handle on the cutting pad. Beyond those parameters, you can let your choice be dictated by personal taste and price. The second of my St Francis icons (dated 2017) was made with 23 ct red gold, which I bought this time for no better reason than that it was older stock being offered at the old price. I like the way its warmer tone sits with the reds and browns of the icon - I have yet to decide whether it will sit comfortably in other pieces.
The view from my desk
Current work, places and events, art travel, and interesting snippets about Christian icons, medieval art, manuscript illumination, egg tempera , gilding, technique and materials.