It is not gold paint. Klimt laid gold leaf onto the canvas by hand, with silver and platinum in places, and the Austrian state bought the result in 1908 before he had finished it. His father engraved gold for a living, and died poor doing it.
Ravenna, 1903
Klimt went to Ravenna in 1903 and saw the sixth-century mosaics in the church of San Vitale: walls of small gold tiles, each set at a slightly different angle, so the gold moves as you walk past it.
What followed in his work is called the golden phase, and The Kiss is where it goes furthest. Leaf is not paint and cannot be brushed on. It has to be laid down in squares, and it keeps its edges and its joins, so up close the surface is a grid rather than a wash of colour. He was not borrowing an effect from the mosaics. He was using their method.
His father Ernst was a gold engraver who worked in the trade all his life and died with nothing in 1892. Klimt grew up watching the most expensive material in the house treated as a job rather than a wonder — weighed out, cut, worked, invoiced.
Who is who, and where they are standing
The two bodies are one gold block, and the only way to tell them apart is the pattern. Hard black rectangles run down his robe. Soft coloured circles and flowers run down hers. The canvas is an exact square, 180 centimetres each way, so there is no landscape and no room, just gold going out to the edges.
Then look at the bottom. The flowered ground stops. She is kneeling on the last of it with her toes bent over the lip, and past that Klimt painted nothing at all — no ground, no drop, no distance, just the end of the meadow and then gold.
He is standing. She is kneeling. His head is bent right down to hers and hers is tipped back, so the only face you can see in the painting belongs to a woman with her eyes shut. The couple have been identified as Klimt and Emilie Flöge for a century, with no evidence either way, which has not slowed anybody down.
Bought before it was finished
It went up in the summer of 1908 at the Kunstschau in Vienna, an exhibition Klimt and his circle built for themselves after walking out on the official art establishment. He hung it under the title Lovers.
The state bought it off the wall for the modern gallery while it was still unfinished, which is not how Vienna had been treating him. A few years earlier his ceiling paintings for the university had been attacked in parliament and never installed, and he had given the money back and taken them home rather than argue.
It has not left the national collection since, and it hangs at the Belvedere. A painting in real gold, bought before it was done, of two people who have not noticed that the ground has run out.
Vienna bought it before he had finished it. A square painting, 180 centimetres each way, and a much smaller square next to your cup.
Some stories are better over a coffee. Fifteen minutes with someone — audio only, not open yet.