The Palette/metal/Beaten or refined from metal

Gold leaf

Beaten to a ten-thousandth of a millimetre, thin enough that a gram covers half a square metre, and thin enough to eat.

Also called shell gold · ormolu (an imitation) · varak

Hex: #D4AF37
RGB: 212, 175, 55
First used: Egyptian, c.2500 BC
From: Everywhere gold was worked; Florence, Kyoto and Jaipur as centres of the craft

What it is

Gold, usually alloyed slightly for workability. Twenty-four carat leaf is essentially pure.

How it is made

Gold is rolled into a ribbon, cut, interleaved between sheets of a special skin or paper, and beaten. The pack is beaten, cut, re-interleaved and beaten again, repeatedly, until the leaf is around 0.1 micrometres thick. At that thickness it is partly transparent and shows green when held to a light, and it will tear if you breathe on it.

Applying it is the other half of the craft. Water gilding lays it on a ground of gesso and bole (a fine clay, traditionally red) using a size of water and glue, and it can then be burnished with an agate to a mirror finish. Oil gilding uses an oil size, cannot be burnished, and gives a matt result. The red bole under water gilding is why worn gilding shows red, and why that red is faked in reproduction furniture.

Shell gold is leaf ground up with honey or gum into a paint, so it can be used with a brush for fine work. It is the most expensive watercolour in the world.

Gold leaf, Very thin gold used in art. Wikipedia's description, not ours.

The history

Gold is not a pigment and it does not behave like one. A pigment scatters light; gold reflects it directionally, which means gilding changes as you move and as the light moves. That is why gold in a church or a temple is not decoration in the way a painted colour is. It is a light source that responds to candles, and it was designed for candles. Seen under museum floodlights it looks like flat yellow metal, which is a fair description of the wrong viewing condition.

Byzantine and medieval gold grounds, Japanese kinpaku and the Kanazawa leaf industry, Thai and Burmese temple gilding, Indian varak on sweets and in painting, illuminated manuscripts, Klimt. Every tradition that could afford it arrived at the same conclusion: put the gold behind the figure and let the light do the rest.

It is also edible and legally a food additive (E175) which is how it turns up on mithai, on chocolate, and on the sort of restaurant dish that gets photographed. Gold's chemical inertness is the reason it is safe to eat and the reason it has never tarnished on a single object in three thousand years.

Where it is used

Icons, manuscripts, temple and church interiors, picture frames, bookbinding, signwriting, domes, food, and cosmetics. Reverse-glass gilded signwriting is still a live craft and is the shiniest type you will ever see.

For brand work, the thing worth understanding is that metallic is not a colour and cannot be specified as one. There is no hex for gold. The swatch above is a convention, a flat yellow-brown that stands in for an event that requires a light source and a viewing angle. If your identity uses gold, it has to be specified as a material per substrate: a foil for print, a Pantone metallic for offset, an anodised finish for metal, and something entirely different for screen, where the only honest options are a gradient or an animation. A brand that hands a printer #D4AF37 and asks for gold will get mustard.

Go and look at it

The mosaics of San Vitale
Ravenna, Italy, in situ
Gold tesserae set at deliberately varied angles so the whole wall shimmers as you walk. The unevenness is the technique.
Kanazawa gold leaf workshops
Ishikawa, Japan
Around ninety-nine per cent of Japan's gold leaf. You can watch the beating and buy leaf thin enough to be translucent.
Varak on mithai
Any Indian sweet shop
The same material as a Byzantine altarpiece, on a barfi, for a few rupees.

How it behaves

Made of: Gold, usually alloyed slightly for workability. Twenty-four carat leaf is essentially pure.
Opacity: Opaque. It covers what is under it.
Lightfastness: Permanent. It will outlive the thing it is painted on.

Chemically inert. It does not tarnish, which is why ancient gilding survives intact.
Directional reflection, not scattering. It needs a point light source to work.
At leaf thickness it is semi-transparent and transmits green light.

The numbers

All derived from the hex, never typed beside it

HEX: #D4AF37; What a browser and a design file want.
RGB: 212, 175, 55; The same three numbers in base ten. Light, not ink.
HSL: 46°, 65%, 52%; Hue, saturation, lightness, how a person describes a colour.
CMYK: 0, 17, 74, 17; Arithmetic only. A real separation depends on the press, the paper and a profile.
LAB: 73, 1, 63; Perceptual. L* of 73 is how light this actually looks, which HSL gets wrong.

This hex is an approximation, and a page about pigment has to say so. Gold leaf is a substance. A ground mineral scatters light from thousands of separate grains at slightly different angles, and no single sRGB value is that event. It is a flat average of a photograph of it, and the real thing is outside what a screen can emit. Use the number to specify a screen colour. Do not use it to judge the pigment.

Where it sits on the wheel

Hue 46°

Its opposite, by the diagram

#D4AF37

#375CD4

The arithmetic opposite, 180° round in HSL. Useful, and not the same as the opposite a painter mixing pigment would name, that wheel was built for paint.

Lighter and darker

Towards white

#D4AF37

#DABB55

#E1C773

#EAD79B

#F2E7C3

#F9F3E1

Mixing with white does not only lighten, it dulls and cools. This is why a pale tint of a brand colour so often looks chalky, and why a designed light shade beats a generated one.

Towards black

#D4AF37

#B4952F

#947A27

#6A581C

#403511

#201A08

Mixing with black kills the hue as it darkens. A better dark is usually the colour plus its neighbour round the wheel, which is what every painter does instead.

Can you set type on it

Handgloves

White on it
2.10:1 · Fails

Handgloves

Black on it
9.99:1 · AAA

Handgloves

It on paper
2.00:1 · Fails

Handgloves

It on ink
8.70:1 · AAA

4.5:1 is the floor for body text and 3:1 for large text, by WCAG. Treat it as a minimum you may not go under rather than as a target: plenty of pairs pass at 4.6:1 and are still unpleasant to read for a page, and the checker will not tell you that.