What Is Gilding?
Gilding is the craft of covering a surface with a very thin layer of real gold, called gold leaf. In painting, it created the shimmering gold backgrounds, halos and borders of medieval and early Renaissance art. Done well, the gold is burnished to a mirror shine, so a painted saint seems to float in pure, glowing light.
It is not gold paint.
It is actual gold, hammered thinner than paper and laid by hand.
Gilding, the basics
What it is: applying real gold leaf to a surface.
The material: gold beaten into sheets thinner than a hair.
The look: a brilliant, reflective, burnished gold.
The home: medieval and early Renaissance panels and manuscripts.
The two methods: water gilding (burnished) and oil gilding (matte).
Gold thinner than paper
The wonder starts with the material itself.
Gold can be beaten into leaves so thin they are almost transparent, far thinner than a sheet of paper, light enough to drift on a breath. The gilder lifts these fragile leaves with a special brush and lays them onto a prepared surface, where they bond and can then be polished. A tiny amount of gold can cover a surprisingly large area, which is part of how medieval workshops afforded so much shine.
A coin of gold could gild a whole saint.
The bed beneath the gold
Burnished gilding depends entirely on what lies underneath.
For the brightest, mirror-like gold, the panel is first coated in gesso, then a soft red clay layer called bole. The gold leaf is laid over the bole and burnished with a smooth stone tool until it shines. The artist could also press patterns into the gesso first, so the finished gold carries tooled halos and borders that catch the light. The same glowing gold fills the pages of an illuminated manuscript.
The shine you admire is really the polish of the clay you never see.
Water gilding versus oil gilding
There are two main ways to lay the gold, with different looks.
Water gilding, used for the finest panels, lets the gold be burnished to a brilliant mirror, but it is delicate and demanding. Oil gilding sticks the leaf down with a slow drying oil size, giving a softer, matte gold that is tougher and good for frames and architecture. The choice depends on whether you want dazzling brilliance or durable warmth.
Mirror or glow: the method decides which gold you get.
Why so much gold
The gold was never only decoration.
In a dark medieval church lit by candles, a gold ground turned a painting into a source of light, flickering and alive, lifting the holy figures out of earthly space into a timeless, heavenly realm. Gold was also simply precious, a fitting offering for the divine, often used with glowing egg tempera. When perspective and naturalism arrived, the gold ground slowly gave way to painted skies, but for centuries, heaven was gold.
The background was not empty. It was the light of the sacred.
The glow is everywhere in early Italian art. Gentile da Fabriano’s Adoration of the Magi blazes with tooled gold in the Uffizi, and the Wilton Diptych in the National Gallery sets its figures against burnished gold.
Common questions about gilding
What is gilding? Applying a very thin layer of real gold leaf to a surface.
Is it gold paint? No. It is actual gold beaten into ultra thin sheets and laid by hand.
What is gold leaf laid on? Often a gesso ground with a red clay layer called bole, then burnished.
What is the difference between water and oil gilding? Water gilding can be burnished to a mirror shine. Oil gilding is matte and more durable.
Why did medieval art use so much gold? It caught candlelight, signaled the sacred, and lifted figures into a heavenly realm.
The light that came from the wall
We are used to paintings that show light. A gold ground does something stranger: it gives off light.
In a flickering candlelit church, those burnished gold backgrounds genuinely glowed, turning a wooden panel into a small sun. Gilding is the moment art stopped depicting radiance and simply became radiant. Five centuries later, in a dim museum gallery, a gold ground still does it, pulling every scrap of light in the room toward a saint who seems lit from within.