Fracture Categories


Description

This category includes damage that extends beyond the paint and preparatory layers and affects the wood. The damage is often visible from both the front and rear views, although restoration work may obscure the damage when viewed from the front.

Splits indicate damage to the wood that is directly associated with the joins between panels; disjoins indicate damage associated with separation between the individual boards that make up the panel painting.

Detail of a painting from Knole House showing an example of IMPASTOW major crack type, which are splits and disjoins in the wooden boards


Description

This category of minor crack includes only isolated cracks (that is, those not in a network) that originate at the edge of the visible panel as viewed from the front.

Detail of a painting from Knole House showing an example of IMPASTOW minor crack type B, which are edge cracks where the panel meets the frame


Description

This category of minor crack includes only isolated cracks (that is, those not in a network) that are located in the spandrels and do not originate at the edge of the visible panel as viewed from the front.

Detail of a painting from Knole House showing an example of IMPASTOW minor crack type C, which are isolated cracks in the spandrels


Description

This category of minor crack includes only isolated cracks (that is, those not in a network) that are located within the portrait ovals as viewed from the front.

Detail of a painting from Knole House showing an example of IMPASTOW minor crack type D, which are isolated cracks in the portrait ovals


Description

A series of connected cracks are considered to be a network. This category of crack includes connected cracks that are both large and located within gilding as viewed from the front. Large island networks are those that are longer than 5mm and that have islands that are on average larger than 2mm.

Detail of a painting from Knole House showing an example of IMPASTOW network crack type A, which are large connected islands of cracks within the gilding


Description

A series of connected cracks are considered to be a network. This category of crack includes connected cracks that are small and located within gilding as viewed from the front. Small island networks are those that have islands that are on average no larger than 2mm.

Detail of a painting from Knole House showing an example of IMPASTOW network crack type B, which are small connected islands of cracks within the gilding


Description

A series of connected cracks are considered to be a network. This category of crack includes connected cracks that have an overall vertical orientation and are located within the portrait oval as viewed from the front. The overall vertical direction indicates that these cracks will typically follow the grain of the wood.

Detail of a painting from Knole House showing an example of IMPASTOW network crack type C, which are vertical networks of cracks within the portrait oval


Description

A series of connected cracks are considered to be a network. This category of crack includes connected cracks that appear to be associated with the movement between the frame and panel as viewed from the front, and do not extend into the spandrels or portrait ovals.

Detail of a painting from Knole House showing an example of IMPASTOW network crack type D, which are edge networks of cracks where the panel meets the frame


Description

A series of connected cracks are considered to be a network. This category of crack includes only those associated with the oval decoration found on each panel, marking the delineation between the gilded spandrels and the oval portraits. Note that cracks in this category do not necessarily follow the grain of the wood.

Detail of a painting from Knole House showing an example of IMPASTOW network crack type E, which are edge networks of cracks in the red/brown oval decoration


Description

A series of connected cracks are considered to be a network. This category of crack includes only those those found only in the spandrel decoration. Note that the networks in this category appear amorphous, and do not appear to follow the grain of the wood.

Detail of a painting from Knole House showing an example of IMPASTOW network crack type F, which are edge networks of cracks in the red/brown spandrel decoration


Description

This category of delamination includes only that which has occurred between the blue paint layer of the spandrels and the later preparation layer associated with the spandrel gilding.

Detail of a painting from Knole House showing an example of IMPASTOW delimitation type A with blue paint layer exposed


Description

This category of delamination includes only that which has occurred within the preparatory ground layer of the later gilding within the spandrels.

Detail of a painting from Knole House showing an example of IMPASTOW delimitation type B with ground layer exposed


Description

This category of delamination includes all areas of paintings where wood is clearly exposed in high-resolution imaging.

Detail of a painting from Knole House showing an example of IMPASTOW delimitation type C with panel wood exposed


Description

This category of delamination includes those instances in which a dark paint layer was visible, often located along the intersection at which the front of the panel meets the frame.

Detail of a painting from Knole House showing an example of IMPASTOW delimitation type D with dark paint layer exposed


Description

This category of delamination includes those instances that display clear past delamination, which has been retouched, obscuring the ability to determine the layers between which the delamination has occurred.

Detail of a painting from Knole House showing an example of IMPASTOW delimitation type E with the exposed layer undetermined due to retouching


Description

This category includes all examples of tenting, where delaminated layers around cracks are raised in a pattern of peaks.

Detail of a painting from Knole House showing an example of tenting for IMPASTOW