FORENSIC ANALYSIS
In recent years dendrochronology, CT-Scanning, Infra-red, Ultra-violet and other forensic techniques have developed hand in hand with improved restoration techniques. I am able to offer a range of analytical techniques for examining instruments from my studio in Oxford and I am further able to work other specialists for dendro and CT-Scanning. For these, I am able to provide interpretation of the results, which otherwise can be difficult to understand and sometimes misleading. Full condition reports similar to a forensic autopsy can be time-consuming to produce, and may require several days with the instrument. They are necessarily costly but may be advisable when considering a very valuable instrument much like a surveyors report prior to purchasing a house. Abbreviated consultations are also possible in which I am able to produce imagery, and go through the areas of interest at a much reduced cost. I am always happy to discuss what may be required on a case-by-case basis.
CONDITION REPORTS
How I work with areas of interest.
The illustration opposite taken under ultra violet light shows my preferred methodology of ‘areas of interest’ in which I am able to isolate areas of restoration, and areas in which original or historic features of the instrument may raise questions that can be satisfactorily be resolved (Areas 4&9, for example are original extensions of wood added by the maker as part of the original process). I will use a variety of analytical techniques to explore each area individually. In my experience this approach which is similar in style to an autopsy and providing a narrative description of each area is more transparent than drawings. It is often more important to assess the quality of restoration of a damaged area than to show where the damage is.
Illustrated is the Ex-Amaryllis Fleming cello by the Brothers Amati.
INFRA-RED REFLECTIVE PHOTOGRAPY
Infra-red for crack analysis.
Infra-red at 850 nanometers will travel through the varnish of most instruments and reflect off the wood. Carbon, which appears as a component of glue is highly absorbant of IR waves causing even near-perfect cracks to appear as a black line, and it is thus possible to see under the varnish in order to see the any surface damage. This form of analysis is often the most helpful for showing where areas of interest can be found, whilst other techniques can be helpful for investigating these areas and providing an opinion about the security of any restoration.
Illustrated is one of three instruments by Jacob Rayman made in Southwark in 1641 which together constitute the earliest dated English stringed instruments extant, likely commissioned for the Chapel Royal of King Charles I. In this case, an analysis of woodworm grazing the surface of the instrument shows it to be in a more structurally sound state than it appears under daylight conditions.
INFRA-RED REFLECTIVE PHOTOGRAPY
Infra-red for crack analysis.
Infra-red at 850 nanometers will travel through the varnish of most instruments and reflect off the wood. Carbon, which appears as a component of glue is highly absorbant of IR waves causing even near-perfect cracks to appear as a black line, and it is thus possible to see under the varnish in order to see the any surface damage. This form of analysis is often the most helpful for showing where areas of interest can be found, whilst other techniques can be helpful for investigating these areas and providing an opinion about the security of any restoration.
Illustrated is one of three instruments by Jacob Rayman made in Southwark in 1641 which together constitute the earliest dated English stringed instruments extant, likely commissioned for the Chapel Royal of King Charles I. In this case, an analysis of woodworm grazing the surface of the instrument shows it to be in a more structurally sound state than it appears under daylight conditions.
HIGH INTENSITY RED LIGHT
Photographic enhancement for dendrochronology
Using a 620 nanometer red light source at 1,200 mW provides some of the enhancement of infra-red, but it photographs within the visual light spectrum to which modern cameras are calibrated. It is especially useful in cases where varnish and dirt are too opaque to allow for a successful dendrochronological analysis. The process does not guarantee success, but it is valuable if an initial dendrochronological analysis proves unsuccessful.
Illustrated is a detail the viola (above) by Jacob Rayman made in Southwark in 1641. The darker areas towards the bottom of the image are a combination of preserved original varnish and a layer of black soot mixed with rosin dust that appear opaque and completely obscure the grain when viewed under normal light conditions.
ULTRA-HiGH INTENSITY WHITE LIGHT
Another system for providing clear annual rings for dendrochronology is the use of the same ultra high intensity light that I also use for raking light photographs.
Illustrated is an English violin by Nathaniel Cross, c.1730 obliquely lit with a super-high intensity light source.
ULTRA-HiGH INTENSITY WHITE LIGHT
Another system for providing clear annual rings for dendrochronology is the use of the same ultra high intensity light that I also use for raking light photographs.
Illustrated is an English violin by Nathaniel Cross, c.1730 obliquely lit with a super-high intensity light source.
ULTRA-VIOLET AnALYSIS
Ultraviolet lightwaves are highly reflective off any surface. As a result they provide indications of different varnish layers and the different types of varnish and pigment appled. The problem is that the short wavelength means that UV is highly influenced by the power of the light source and its distance from the subject, so that most commercially available light sources provide low intensity imagery. The high intensity light source that I use provides clear photographs that help both to provide high quality analysis and to be able to communicate it successfully.
Illustrated is the back of a Cremonese violin by Lorenzo Storioni, circa 1780 that was reworked in the 19th century to be sold as the work of Guarneri del Gesù. We can see elements of bare wood, of the whitish and yellowish layers of ground and pigemented varnish, orange shellac and oil varnish retouching, and bright reflective evidence of glued cracks. The state of this violin is out of the ordinary, and it is unusual for them to look quite so like a Jackson Pollock painting, but it serves as an extreme example of what can be revealed by UV analysis..
INFRA-RED PENETRATIVE PHOTOGRAPHY
Interior analysis.
The low-energy properties of infra-red light mean that it is able to penetrate materials such as wood and paper. It is a very safe and effective way to look through materials, with a result that is similar to an X-Ray or CT-Scanning without incurring significant cost and logistical problems. It is good for showing patches and cleats, and for both finding woodworm tunnels that have been open, and those that have been filled.
Illustrated is a violin by Jack Lott illuminated from behind in order to analyse the printer’s ink used for the production of the label.. His are some of the most convincing reproductions of original Italian labels, and their success is one of the distinctive elements of his work.
INFRA-RED PENETRATIVE PHOTOGRAPHY
Interior analysis.
The low-energy properties of infra-red light mean that it is able to penetrate materials such as wood and paper. It is a very safe and effective way to look through materials, with a result that is similar to an X-Ray or CT-Scanning without incurring significant cost and logistical problems. It is good for showing patches and cleats, and for both finding woodworm tunnels that have been open, and those that have been filled.
Illustrated is a violin by Jack Lott illuminated from behind in order to analyse the printer’s ink used for the production of the label.. His are some of the most convincing reproductions of original Italian labels, and their success is one of the distinctive elements of his work.
CT-SCANNING
CT-Scanning is one of the most effective ways of examining an instrument, and I am able to arrange for these services where necessary. However, this can be logistically challenging, difficult to facilitate at short notice and very costly to undertake and to analyse. Moreover, in the majority of instances the other methods of investigation will produce a thoroughly satisfactory result, therefore it is only really useful under special circumstances or to answer particularly complex questions: CT Scans, for example, have prove helpful before undertaking complex restorations in order to fully assess the extent of old repairs.
N.B. CT-Scans at standard medical settings are insufficient for an accurate assessment. Whilst they may show physical anomalies such as patches and studs, they do not have enough resolution to examine cracks and can lead to misleading results.
Illustrated is an Italian viola by Paolo Castello of Genoa, circa 1770, showing the extent of internal patches, half-edging, soundhole restoration and crack repairs.
RAKING LIGHT
Raking light is far more helpful for flat surfaces such as viols, lutes, guitars and double basses, where a strong light cast obliquely over the surface creates shadows. It occasionally proves invaluable with violin-family instruments.
Illustrated is a photograph taken of a lute soundboard from by Sixtus Rauchwolff, 1596 that I took at the Metropolitan Museum of Art as part of a conservation assessment.
RAKING LIGHT
Raking light is far more helpful for flat surfaces such as viols, lutes, guitars and double basses, where a strong light cast obliquely over the surface creates shadows. It occasionally proves invaluable with violin-family instruments.
Illustrated is a photograph taken of a lute soundboard from by Sixtus Rauchwolff, 1596 that I took at the Metropolitan Museum of Art as part of a conservation assessment.
FOR PAINTINGS
The usefulness of infra-red photography for painting analysis is already well established and on occasion I am able to make the technology available for studies of paintings and other objects.
Illustrated is a detail from a version of the 1834 London portrait of Nicolo Paganini by George Pattern. Of the three versions by the artist this is the less complete, but Infra-Red analysis of the image shows underpainting indicative that it is from an early compositional stage, and helps to establish its primacy as the preparatory study from life.
LABEL AnALYSIS
Forensic typologies of genuine, fake and reproduction labels.
Non-original labels present significant challenges to violin expertise, and these range from facsimile labels inserted by experts that ethically and accurately reflect a secure attribution of an instrument, all the way to imitation labels in mass produced instruments that self-evidently make no claim to be authentic. Most difficulties arise in the middle-ground, especially where reference works published in over a century ago that were intended to aid identification included phot0-lithograph reproductions of labels that inevitably have been further copied put to misuse. Many of these are relatively easy to identify when reproduction processes are understood, but some can be very convincing. Where it is appropriate I am able to apply a range of analytics to examining labels in-situ in instruments to assess their authenticity. Illustrated is a sheet of labels from my reference collection printed on laid paper from the Arches-Moulin du Gué paper mill around 1890-1900 by the Autotype Company for W.E. Hill & Sons. See the case study below.
LABEL AnALYSIS
Forensic typologies of genuine, fake and reproduction labels.
Non-original labels present significant challenges to violin expertise, and these range from facsimile labels inserted by experts that ethically and accurately reflect a secure attribution of an instrument, all the way to imitation labels in mass produced instruments that self-evidently make no claim to be authentic. Most difficulties arise in the middle-ground, especially where reference works published in over a century ago that were intended to aid identification included phot0-lithograph reproductions of labels that inevitably have been further copied put to misuse. Many of these are relatively easy to identify when reproduction processes are understood, but some can be very convincing. Where it is appropriate I am able to apply a range of analytics to examining labels in-situ in instruments to assess their authenticity. Illustrated is a sheet of labels from my reference collection printed on laid paper from the Arches-Moulin du Gué paper mill around 1890-1900 by the Autotype Company for W.E. Hill & Sons. See the case study below.
DENDROCHRONOGLOGY
Second opinions.
Over the last twenty-five years dendrochronology of stringed instruments has become a very rigorously applied scientific process that yields results that are helpful to the authentication of instruments. However as with all rigorous procedures there are complexities relating to how a report can be interpreted and sometimes these can lead to optimistic or misleading attributions. Since dendrochronology emerged as a tool for violin analysis in the late 1990s I have maintained a very close connection with leading practitioners, and in a number of situations my interpretation has proven as valuable as the report itself.
NEW TECHNOLOGIES
I am working with colleagues to examine ways of producing 3d modelling of key instruments in order to better inform the craft of traditional violin making.
I can’t say anything more yet, except that here is a plastic copy of the Messiah…
NEW TECHNOLOGIES
I am working with colleagues to examine ways of producing 3d modelling of key instruments in order to better inform the craft of traditional violin making.
I can’t say anything more yet, except that here is a plastic copy of the Messiah…
CASE STUDIES
For a while I have been collecting case studies of forensic techniques and observations, as part of a collaborative effort to advance forensic study of violins with colleagues all over the world. My Enhanced Condition Report Casebook can be viewed through the following link, and below are a number of studies that demonstrate the usefulness of the techniques that I use.
JACK LOTT, STORIONI AND THE CANNONE DEL GESU.
Recently I was asked to assess a very good violin that had been bought without attribution at auction. The soundholes were those of Paganini’s Il Cannone, but in every other respect it deviated from Guarneri’s work. In the following blog from my forensic casebook, I explore the process that led to eventual identification as originally a violin by the late Cremonese maker Lorenzo Storioni, ‘upgraded’ with a great deal of intervention to pass for a Guarneri del Gesú by the hand of Jack Lott. At the time that it passed through Lott’s hands in the mid-19th century, there were very few del Gesú violins known in London (there are less than 200 currently known), and this almost certainly passed as a genuine example.
FACsimile labels of the london autotype co.
Over the years I have come across several labels in violins sold by W. E. Hill & Sons that have raised questions over their authenticity. There are, for example, far too many violins by Edward Pamphilon with a label for 1668, and dendrochronology showed that at least one of these post-dated the label date by a sizeable margin. Several candid comments found in parts of the Hill papers lead to the London Autotype Company at 74 New Oxford Street demonstrating a practice that they engaged in around the turn of the 20th century that was never meant to deceive, but now adds to the complexities of ethical and unethical facsimile labels.
FACsimile labels of the london autotype co.
Over the years I have come across several labels in violins sold by W. E. Hill & Sons that have raised questions over their authenticity. There are, for example, far too many violins by Edward Pamphilon with a label for 1668, and dendrochronology showed that at least one of these post-dated the label date by a sizeable margin. Several candid comments found in parts of the Hill papers lead to the London Autotype Company at 74 New Oxford Street demonstrating a practice that they engaged in around the turn of the 20th century that was never meant to deceive, but now adds to the complexities of ethical and unethical facsimile labels.