Cracking (Craquelure)

Craquelure is the technical name for 'cracking' in an oil painting

Craquelure is the single most obvious sign of old age and change in an oil painting.

It is a French term, used generically, to refer to the cracks or 'seperation', visible when the surface of the paint 'literally seperates' from the base, revealing the ground colour beneath.

The size, shape and patterns of the craquelure can vary enormously, and can be described accordingly; spoke cracks, frame cracks, grid cracks, garland and spiral, corn ear and also brush stroke cracks are examples of the various patterns.

Craquelure is not in itself harmful to the painting, in fact fine craquelure can add to the 'quality' of its patina, that only age can bring - there is an aesthetic balance to consider!

James Mattock - craquelure example

However, in the painting below (a 19th century 'cattle portrait' by Provincial artist James Mattock), the amount of craquelure detracts from the quality of the image, particularly in the areas involving white pigment. This made the painting look 'rather grubby' and undermined the whole charm of the work.

Click the images to see close-ups of the before and after.
The clients where absolutely overjoyed with the transformation of their treasured family heirloom

Jules Cave - craquelure example

Prior to cleaning, the dirt and old varnish obscured the overpainted craquelure, in this beguiling 19th century portrait by French artist Jules Cave.

In order to return the masterful colour tones of the portrait, much of the previous restoration had to be removed and then retouched, matching the original pallette.

Bitumised Craquelure

It became fashionable in the early 19th century to experiment in mixing liquid bitumen with black pigment. Over time the dark tones in particular, of some of these paintings have undergone a chemical change.

This detail of a late 19th Century Highland painting by Robert Cleminson shows moderate 'Bitumisation'. Early 19th Century examples can be far more dramatic!

In extreme examples the bitumen has oxidised and blistered forming deep, wide and unsightly cracks. This transformation can make quite an impact on the texture of the paint itself, and requires quite unique strategies for cleaning and re-touching.