University Post
University of Copenhagen
Independent of management

Science

Searching for pearl grey

For centuries, painters used the term on bills and old invoices. But what colour is it?

The old stairways and walls in the central campus building at the University of Copenhagen have it. And it is itemised on bills to the University of Copenhagen from 1803.

It is pearl grey, a specific shade of grey paint that somehow seems to elude modern colour description. Anna Hansen, who is doing her Bachelor’s degree as a conservator, is taking a closer look.

»There are many conservators that come across pearl grey in the old invoices,« she says, »but nobody knows what it is.«

Strips off layer after layer

The University Post met Anna Hansen taking samples off the stairways of the Professor Villa on Central Campus.

On these same stairways, other, earlier, conservators have stripped off segments of the paint, so they can analyse backwards in time.

»By way of different chemicals, depending on the paint, you can strip off layer after layer,« Anna explains.

Camera matches the shades

Anna herself is using a pen-like instrument to take samples, a bit like as if it was a physician taking a muscle biopsy with a syringe. First layer is from 1740 (not pearl grey), then pearl grey, and a whole series of different shades.

See the ‘biopsy’ of the paintwork in this image here.

These samples will be put under the microscope for later analysis.

A camera is set up to take pictures that match the exact shade, closest possible to the real ‘pearl grey’.

Just in the invoices

For Anna, the quest continues.

»When you search for pearl grey in the literature, there is almost nothing there, only in the invoices. I am just really interested in finding out what it is«.

Check out the full gallery of Anna’s latest research here.

miy@adm.ku.dk

Stay in the know about news and events happening in Copenhagen by signing up for the University Post’s weekly newsletter here.

Latest