Specialist model 1
Paintings
Oil, acrylic, tempera and mixed media works on panel, canvas or board.
Essential evidence
artistmediumdimensionsconditionsignature
High value signals
- catalogue image match
- artist signature
- documented title
- provenance
- exhibition label
Common traps
- print presented as painting
- studio copy
- after artist
- condition hidden by varnish
- false signature
Preferred sourcesNationalmuseum, The Met, Europeana, Rijksmuseum, K samsök, Artnet, Artprice
Minimum comparables4
Source strength95%
Liquidity prior82%
Specialist model 2
Prints and works on paper
Prints, drawings, watercolours, gouache, lithographs and etchings.
Essential evidence
artisttechniqueeditionsheet_sizecondition
High value signals
- edition number
- printer blindstamp
- paper watermark
- catalogue raisonné reference
- hand signature
Common traps
- poster
- facsimile
- later impression
- unsigned edition
- trimmed margins
Preferred sourcesNationalmuseum, The Met Drawings and Prints, Europeana, V&A, Art Institute of Chicago, Artnet
Minimum comparables5
Source strength94%
Liquidity prior78%
Specialist model 3
Sculpture
Bronze, stone, wood, plaster and mixed material three dimensional works.
Essential evidence
artistmaterialdimensionsfoundryeditioncondition
High value signals
- foundry mark
- edition number
- documented cast
- base inscription
- 3D silhouette match
Common traps
- posthumous cast
- decorative reproduction
- resin sold as bronze
- missing base
- unrecorded edition
Preferred sourcesThe Met, Smithsonian Open Access, Europeana, V&A, Nationalmuseum, Artnet
Minimum comparables3
Source strength91%
Liquidity prior68%
Specialist model 4
Ceramics and porcelain
Studio ceramics, porcelain, faience, stoneware and earthenware.
Essential evidence
makerfactorymaterialmarkdimensionscondition
High value signals
- factory mark
- artist monogram
- model number
- documented glaze
- rare production period
Common traps
- later factory mark
- restoration
- marriage of parts
- modern reproduction
- cracks not photographed
Preferred sourcesV&A, The Met, British Museum, DigitaltMuseum, K samsök, Europeana
Minimum comparables5
Source strength97%
Liquidity prior80%
Specialist model 5
Art glass
Studio and factory art glass, engraved glass and limited design production.
Essential evidence
designerfactorysignaturemodeldimensionscondition
High value signals
- engraved signature
- factory code
- documented model
- rare colourway
- prototype or unique piece
Common traps
- acid etched imitation mark
- polished damage
- mass production
- misread model code
- internal crack
Preferred sourcesV&A, The Met, DigitaltMuseum, K samsök, Europeana, Corning Museum of Glass
Minimum comparables4
Source strength91%
Liquidity prior76%
Specialist model 6
Silver and metalware
Silver, goldsmith work, pewter, bronze decorative objects and hollowware.
Essential evidence
makerhallmarksfinenessweightdate_lettercondition
High value signals
- complete hallmark set
- rare maker
- assay office
- date letter
- documented royal or exhibition provenance
Common traps
- silver plate
- weighted base
- mixed fineness
- altered marks
- melt value mistaken for art value
Preferred sourcesV&A, The Met, DigitaltMuseum, K samsök, British Museum, hallmark authorities
Minimum comparables5
Source strength98%
Liquidity prior84%
Specialist model 7
Jewelry
Artist jewelry, antique jewelry, signed design jewelry and precious objects.
Essential evidence
makermarksmetalgemstonesweightmeasurementscondition
High value signals
- maker signature
- assay marks
- gem report
- documented design
- original fitted case
Common traps
- synthetic stone
- composite stone
- later replacement
- plated metal
- brand mark imitation
Preferred sourcesV&A, The Met, British Museum, Smithsonian, Europeana, commercial jewelry archives
Minimum comparables4
Source strength90%
Liquidity prior88%
Specialist model 8
Furniture and design
Designer furniture, lighting, mirrors and documented industrial design.
Essential evidence
designermanufacturermodelmaterialsdimensionscondition
High value signals
- manufacturer label
- model number
- early production detail
- documented provenance
- original surface
Common traps
- later licensed production
- unlicensed copy
- replacement upholstery
- altered dimensions
- missing label
Preferred sourcesCooper Hewitt, V&A, DigitaltMuseum, K samsök, The Met, manufacturer archives
Minimum comparables5
Source strength97%
Liquidity prior86%
Specialist model 9
Photography
Vintage, later and contemporary photographic prints with documented processes and editions.
Essential evidence
photographerprocessprint_dateeditiondimensionsprovenance
High value signals
- negative date and print date
- photographer stamp
- edition
- gallery label
- vintage print provenance
Common traps
- later print sold as vintage
- estate print
- open edition
- faded colour
- cropped reproduction
Preferred sourcesThe Met Photographs, Smithsonian, Europeana, K samsök, Nationalmuseum, museum photo archives
Minimum comparables4
Source strength92%
Liquidity prior70%
Specialist model 10
Clocks and watches
Mechanical watches, clocks and artistically significant timepieces.
Essential evidence
makerreferenceserialmovementcase_materialconditionservice_history
High value signals
- reference and serial consistency
- rare dial
- original movement
- documented production run
- original box and papers
Common traps
- service dial
- frankenwatch
- replacement movement
- polished case
- counterfeit reference
Preferred sourcesThe Met, British Museum, Smithsonian, manufacturer archives, auction price databases, watch reference databases
Minimum comparables6
Source strength89%
Liquidity prior94%