Defect Atlas — Paintings

A canvas support that has lost flexibility, strength or integrity over time.

Brittle, brown or discoloured fabric; reduced strength under light handling; sometimes broken threads at the tacking edge.

Age, environmental exposure, original fibre type and past treatments may contribute to canvas degradation.

• extent and distribution of weakness
• condition of the tacking edges
• evidence of past lining or stabilisation
• any visible thread breakage

“The canvas appeared brittle and discoloured across the reverse, with broken threads visible along the lower tacking edge.”

Linear breaks through the canvas support, visible from front or reverse.

Open or closed tears with possible associated paint loss, distortion or thread displacement.

Impact, handling, sustained tension or weakened fabric may contribute to tearing.

• location, orientation and length
• any associated paint loss or distortion
• evidence of past repair
• stability of edges of the tear

“A horizontal tear of approximately 80 mm was recorded in the lower right quadrant, with associated paint loss along the edges.”

Areas where the canvas, panel or other support is locally missing.

Visible voids, sometimes infilled with later material; associated paint loss around the perimeter.

Impact, past damage or insect activity in panel paintings may contribute.

• location and approximate size
• presence of fills or infills
• condition of surrounding paint
• evidence of past repair

“A small hole approximately 12 mm across was recorded in the upper left quadrant, with associated paint loss extending a further 5 mm around the perimeter.”

Through-thickness or partial cracking of a wooden panel support.

Visible cracks following or crossing the grain; sometimes with associated movement or paint loss above.

Moisture cycling, panel restraint, original construction and species behaviour may contribute.

• location, orientation and length
• any associated paint loss along the crack
• evidence of movement
• relationship to grain direction

“A vertical panel crack of approximately 200 mm was recorded in the lower section, following the grain and with associated paint loss in places.”

Separation along original or later joins between boards of a panel.

Visible gaps along board joins; sometimes with associated paint or ground loss; misalignment of board surfaces.

Adhesive failure, moisture cycling and panel movement may contribute.

• location and extent of separation
• alignment of adjacent boards
• any associated paint loss
• evidence of past consolidation or repair

“A split was recorded along the central join of the panel, with approximately 1 mm of separation and associated paint loss.”

Evidence of wood-boring insect activity within a panel support.

Exit holes on front or reverse; tunnels visible at edges; sometimes associated frass.

Wood-boring insect activity, current or historic, may produce these features; species identification is not implied.

• extent and distribution of holes
• presence of fresh frass
• depth and density of tunnelling where assessable
• evidence of structural weakening

“Insect exit holes were recorded across the reverse of the panel, with no fresh frass observed at the time of survey.”

Departures from the plane of the canvas, including bulges, hollows or general distortion.

Visible undulations on the painted surface; out-of-plane areas when viewed in raking light; sometimes associated paint cracking.

Loss of tension, sustained loading, moisture cycling or local damage to the support may contribute.

• location and approximate extent of distortion
• association with handling marks or damage
• any related paint cracking
• evidence of progression

“A bulge of approximately 20 mm across was recorded in the lower right quadrant, visible in raking light and associated with a small area of paint cracking.”

A canvas that has lost tension across the stretcher.

Visibly loose fabric; reverberation under light tapping; corner sagging; sometimes general distortion of the painted image.

Age, environmental cycling, original keying or stretcher movement may contribute.

• extent of slackness
• condition of corner keys
• any associated distortion or cracking
• evidence of past re-tensioning

“The canvas was recorded as slack across the central area, with reverberation under light tapping and corner sagging at the lower right.”

Diagonal distortions of the canvas radiating from the corners of the stretcher.

Linear ridges or troughs running diagonally from the corner; sometimes accompanied by paint cracking along the lines of distortion.

Stretcher geometry, tensioning at the corners and canvas behaviour may contribute.

• extent and prominence of draws
• associated paint cracking
• comparison between corners
• evidence of past re-tensioning

“Corner draws were recorded at the lower corners, with linear distortion visible in raking light and minor paint cracking along the lines.”

Out-of-plane curvature of a wooden panel support.

Visible bow, cup or twist of the panel; sometimes associated paint cracking or loss; difficulty seating in frame.

Moisture cycling, original grain orientation, panel construction and restraint may contribute.

• type and direction of warp
• approximate magnitude
• associated paint cracking or loss
• evidence of seasonal movement where recorded

“Panel warping was recorded across the painting, with approximately 6 mm of convex bow at the centre when measured against a straight edge.”

Marks visible on the painted surface following the lines of the stretcher behind.

Linear ridges, depressions or soiling lines on the front of the painting corresponding to the position of stretcher bars or cross-members.

Contact between canvas and stretcher, dust deposition and pressure may contribute.

• location and extent of marks
• associated paint cracking
• type of mark observed
• evidence of contact with stretcher members

“Stretcher bar marks were recorded across the lower section, with linear soiling and minor paint cracking following the cross-member behind.”

A network of fine cracks within the paint and ground layers associated with long-term aging.

Fine, often interconnected cracks across the painted surface; pattern may follow paint application or vary between areas.

Long-term drying, environmental cycling and characteristics of the paint and ground may contribute.

• extent and distribution
• depth where assessable
• variation across areas of differing colour or impasto
• stability of paint within the network

“Age cracking was recorded across the painted surface, with a fine network particularly visible in the darker passages.”

Wide, often irregular cracks associated with shrinkage of the paint film during drying.

Open, often jagged cracks with exposed underlying layers; sometimes localised to specific passages or pigments.

Original paint formulation, medium-rich passages or thick application may contribute.

• extent and location
• association with particular colours or passages
• stability of paint at crack edges
• evidence of past consolidation

“Drying cracks were recorded in the dark drapery, with several open cracks exposing underlying ground in places.”

Lifting of the paint film along the edges of cracks, producing a cupped or concave appearance.

Raised, curled edges to paint islands; visible in raking light; sometimes sharp to touch.

Differential movement between paint, ground and support may contribute.

• extent and severity of cupping
• association with environmental cycling
• evidence of active loss
• stability of cupped islands

“Cupping was recorded across the central area of the painting, with raised paint edges clearly visible in raking light.”

Cracking that follows a pattern associated with external mechanical events rather than aging.

Concentric or radial crack patterns suggesting impact; linear cracking following handling marks; sometimes with associated distortion.

Impact, pressure, flexing or vibration may contribute to mechanical cracking.

• pattern and location of cracking
• association with handling damage or impact
• evidence of paint loss
• stability of affected paint

“Concentric mechanical cracking was recorded in the upper left quadrant, suggesting a past impact event.”

Wide cracks within an upper paint or varnish layer caused by differential shrinkage over a less mobile layer beneath.

Wide, often gaping cracks revealing the layer beneath; sometimes only in certain coloured passages.

Upper layer applied over an incompletely dried or incompatible layer may contribute.

• location and extent
• association with particular colours or coatings
• depth and width of cracks
• stability of upper layer

“Traction cracking was recorded across the dark glazes in the background, with the underlying paint film visible through wide cracks.”

Paint that is currently lifting, with visible movement or detachment of fragments.

Raised or lifted paint islands; loose flakes resting on the surface or captured in lower edges of the frame.

Loss of adhesion between paint, ground and support; environmental cycling; sustained mechanical stress may contribute.

• location and extent
• size of lifting fragments
• evidence of recent loss
• any retained loose flakes

“Active flaking was recorded across the lower edge of the painting, with several loose flakes captured in the rebate of the frame.”

Areas where paint and possibly ground are absent from the support.

Voids in the painted image revealing ground, support or earlier layers; sometimes with associated fills or retouching.

Past flaking, mechanical damage, abrasion or interventions may contribute.

• location and extent of loss
• depth of loss (paint only, paint and ground, to support)
• presence of fills or retouching
• stability of paint at the perimeter of the loss

“Paint loss was recorded across the lower right corner, exposing ground and with associated retouching surrounding the loss.”

Acute upward lifting of paint along crack lines producing a tent-shaped profile.

Sharp, raised paint along cracks; visible in raking light; high risk of loss.

Severe differential movement between paint and support may contribute.

• location and extent
• height of tented paint
• evidence of recent loss
• stability of affected paint

“Tenting was recorded in the central area, with paint visibly raised along several crack lines.”

Paint that has lost cohesion and releases material as a fine powder.

Soft, chalky surface; material lifts to gentle brushing for diagnostic purposes; sometimes visible only in raking light.

Underbound paint, environmental exposure or past cleaning may contribute.

• extent of powdering
• association with specific colours or passages
• stability under light handling
• any current loss

“Powdering paint was recorded in the matt blue passages, with material released to light brushing for diagnostic purposes only.”

Loss of adhesion between paint layers or between paint and ground, without yet showing surface lifting.

Areas that sound hollow under very light tapping where appropriate; sometimes visible as slight changes in surface reflectance.

Past treatments, environmental cycling and original layer compatibility may contribute.

• extent of suspected cleavage
• any associated surface changes
• evidence of past consolidation
• stability of affected areas

“Possible cleavage between layers was recorded in the upper left passage, with a subtle change in surface reflectance suggesting incipient detachment.”

Yellowing, browning or other discolouration of an applied varnish layer.

Overall yellow or brown cast across the painted image; sometimes with darker pooling in lower passages; alteration of colour balance.

Aging of natural resin varnishes, UV exposure and past coatings may contribute.

• extent and intensity of discolouration
• type of coating where known
• comparison with areas hidden from light by the frame
• any associated surface deposits

“The varnish was recorded as discoloured across the painting, with a marked yellow cast and a tonal difference visible at the rebate where the frame has shielded the surface.”

A whitish or hazy bloom on a varnish surface.

Pale, milky or hazy cast on the varnish; sometimes patchy or following condensation patterns.

Moisture interaction with the varnish, environmental conditions and varnish type may contribute.

• extent and location of bloom
• association with humidity events
• type of coating where known
• any underlying paint changes

“Bloomed varnish was recorded across the upper third of the painting, with a hazy whitish cast over the dark sky passages.”

Networks of cracks within an applied varnish layer.

Fine network of cracks visible in raking light, sometimes only within the varnish layer; differs in pattern from cracking in paint beneath.

Aging of varnish, environmental cycling and original application may contribute.

• extent and distribution of crazing
• whether cracking is within varnish only or affects paint below
• any associated discolouration
• stability of the painted image beneath

“Crazed varnish was recorded across the painted surface, with a fine network visible in raking light and apparently confined to the varnish layer.”

Patchy varnish coverage from past application or selective treatment.

Visible differences in surface gloss, sometimes with brush marks or drip lines.

Local revarnishing, selective coating or past treatment may contribute.

• extent and pattern of unevenness
• evidence of past localised treatment
• associated discolouration
• implications for visual reading of the image

“Uneven varnish application was recorded across the central figure, with brush marks visible in raking light.”

A coating that has not fully cured or has reverted to a tacky state.

Sticky surface to gentle touch where assessment is appropriate; sometimes with dust and debris adhered to the surface.

Original coating, environmental exposure or contamination may contribute.

• extent and location
• presence of adhered debris
• type of coating where known
• stability under handling

“A tacky coating was recorded across the upper background, with fine dust adhered to the affected surface.”

Accumulated dust on the painted surface.

Visible dust layer, particularly on horizontal projections of impasto and within textured passages.

Atmospheric dust, lack of cleaning and proximity to active environments may contribute.

• extent and thickness of dust
• concentration in particular areas
• any embedded debris
• associated stability of paint beneath

“Surface dust was recorded across the painting, with heavier accumulation on the impasto in the foreground passages.”

Adherent dark deposits from past combustion sources.

Dark grey or black film across the surface; sometimes concentrated above former candles, lamps or heating sources.

Historic candles, oil lamps, fires or smoking environments may contribute.

• extent and distribution
• association with known internal sources
• any masking of painted detail
• stability of underlying paint

“Soot deposits were recorded across the painting, with heavier accumulation in the upper section consistent with a former candle position below.”

Fly specks, droppings or other insect residues on the painted surface.

Discrete dark spots, sometimes raised; concentrated near openings or light sources.

Insect activity in the room, proximity to windows and lack of cleaning may contribute.

• extent and distribution
• any masking of painted detail
• evidence of staining beneath
• stability of underlying paint

“Insect deposits were recorded across the upper section, particularly close to the window-facing edge.”

Residues from earlier cleaning materials remaining on the surface.

Cloudy films, streaks, swab marks or salt-like deposits; sometimes localised to specific passages.

Incomplete removal of cleaning agents, surfactants or aqueous residues may contribute.

• extent and location
• association with past cleaning campaigns where known
• any associated paint changes
• documentary references where available

“Residues consistent with past cleaning were recorded across the lower section, with faint streaks visible in raking light.”

Areas of paint applied during earlier interventions to disguise loss or damage.

Differences in colour, texture, gloss or fluorescence under UV examination; sometimes extending beyond the original loss.

Past restoration to cover losses or to alter the appearance of the image may have introduced retouching.

• location and extent
• differences from surrounding original paint
• evidence of discolouration of retouching
• documentary references where available

“Old retouching was recorded across the lower section, visible as slightly mismatched paint extending beyond apparent original losses.”

Past retouching that has discoloured relative to surrounding original paint.

Visibly mismatched retouching, often darker or yellower than the original paint; sometimes prominent under normal viewing.

Aging of retouching media, original mismatch or environmental exposure may contribute.

• extent and location
• degree of mismatch
• any associated paint instability
• evidence of past interventions in the area

“Discoloured retouching was recorded across the figure of the central saint, with several retouches now considerably darker than the surrounding paint.”

Layers of paint applied over original paint that may cover substantial areas of the original image.

Differences in texture, brushwork or fluorescence under UV examination; sometimes covering entire passages.

Past restoration, alteration or modification of the image may have introduced overpaint.

• extent and approximate boundaries
• differences from underlying paint
• evidence of associated retouching
• documentary references where available

“Overpaint was recorded across the sky passage, with brushwork differing from that visible in adjacent original areas.”

An additional support fabric adhered to the reverse of an original canvas.

Secondary fabric visible from the reverse; sometimes with associated edge banding or adhesive residues.

Past structural intervention to support a weakened canvas may have introduced lining.

• type of lining where known
• condition and stability
• associated adhesive type and behaviour
• evidence of impressed texture on the front

“An older glue-paste lining was recorded on the reverse of the painting, in stable condition at the time of survey.”

Fabric or paper patches applied to the reverse of a canvas over tears, holes or weakened areas.

Visible patches on the reverse, sometimes with associated impressed marks on the front.

Past repair to support local damage may have introduced patches.

• location and condition of patches
• type of material and adhesive where known
• associated front-face distortion or paint changes
• evidence of recent or historic application

“A canvas patch was recorded on the reverse over the lower tear, with an associated impressed outline visible on the front of the painting.”

Material applied within areas of paint loss to bring the surface level for retouching.

Visible fills bringing losses to surface level; sometimes recessed, raised or differing in texture from surrounding paint.

Past restoration of losses may have introduced fills, sometimes of differing materials and quality.

• location and extent
• level of fill relative to surrounding paint
• stability and condition
• associated retouching

“Several small fills were recorded along the lower edge of the painting, with one slightly proud of the surrounding paint surface.”

Loss or damage to the frame surrounding the painting.

Cracks, losses, splits or detached ornament; sometimes with associated abrasion to the painting at the rebate.

Handling, transport, environmental cycling or age may contribute.

• location and extent of damage
• loss of decorative elements
• any associated damage to the painting
• stability of repairs

“Frame damage was recorded along the lower right corner, with loss of carved ornament and associated abrasion to the painting at the rebate.”

A frame that no longer provides reliable support to the painting.

Loose fittings, missing backboard, inadequate rebate depth, signs of slippage of the painting within the frame.

Age, past adjustments, alterations or original construction may contribute.

• condition of fittings
• presence and condition of backboard
• evidence of movement within the frame
• implications for display or transport

“The frame was recorded as offering inadequate support, with no backboard fitted and the painting visibly slipped within the rebate.”

Conditions affecting the wooden framework on which a canvas is tensioned.

Cracked, broken, missing or distorted members; missing keys; inadequate clearance from the canvas; insect damage.

Age, environmental cycling, past modifications or insect activity may contribute.

• type of stretcher or strainer
• condition of members and corners
• presence and condition of keys
• associated canvas tension and distortion

“Stretcher issues were recorded at the lower corners, with missing keys and a cracked horizontal member.”

Conditions where the system used to hang the painting appears inadequate.

Corroded or undersized wires, eyelets or fittings; over-stressed mountings; uneven hanging.

Age, original specification, repeated use or environmental exposure may contribute.

• type and condition of hanging system
• evidence of stress or corrosion
• weight of the framed painting where known
• implications for ongoing display

“The hanging wire was recorded as corroded and visibly under tension, with rust staining on the reverse of the frame.”

Physical damage to the painting from a localised impact.

Dents, distortion, cracking radiating from a central point; sometimes with associated paint loss or tearing.

Past handling incidents, contact with adjacent objects or vandalism may contribute.

• location and extent of damage
• evidence of associated tearing or paint loss
• stability of affected paint
• any associated frame damage

“Impact damage was recorded in the upper right quadrant, with concentric cracking around a small distortion of the canvas.”

Loss of surface material from contact, handling or cleaning.

Scuffs, scratches, areas of thinned paint or varnish; sometimes following handling lines or cleaning patterns.

Contact with adjacent surfaces, past cleaning or repeated handling may contribute.

• location and extent
• depth of abrasion
• association with handling zones
• any related paint instability

“Abrasion was recorded across the lower edge of the painting, with scuffs and minor paint thinning along the rebate.”

Tide marks, drips or splash patterns on the painted surface or canvas.

Linear tide marks, run patterns or localised stains, sometimes with associated paint changes; may be visible from the reverse.

Past water incidents, condensation, leaks or environmental events may contribute.

• location, pattern and extent
• evidence of associated paint or varnish changes
• any visible damage to the reverse
• documentary references to past incidents where available

“Water staining was recorded across the lower section, with a tide mark visible on the reverse of the canvas and slight bloom in the varnish above.”

Visible biological growth on the painted surface, varnish or reverse of the support.

Spotty or fluffy growths, often white, grey, black or coloured; sometimes only visible on the reverse.

Sustained high humidity, poor ventilation and organic materials may contribute.

• location and extent
• association with damp storage or display conditions
• any associated staining or paint changes
• evidence of past treatment

“Mould growth was recorded across the reverse of the canvas, with localised dark spotting consistent with sustained humid storage.”

Fading, discolouration or weakening associated with long-term light exposure.

Faded colours, bleached passages, differential reading of the image; sometimes visible only by comparison with areas shielded by the frame.

Sustained exposure to daylight, UV or strong artificial lighting may contribute.

• evidence of fading by comparison with shielded areas
• extent and pattern of affected passages
• lighting conditions in current display
• documentary references to past display

“Light damage was recorded across the painted surface, with a clear tonal difference visible at the rebate where the frame has shielded the paint from light.”