www.DipintiAutenticita.com (last update: 21/01/2010) 

Fond. Gottfried Matthaes

Determining the authenticity of
modern paintings
A section of the Museo d’Arte e Scienza


Information about the authenticity of ancient paintings
on our web site www.paintingsauthenticity.com

The aspiration of painters in the last 100 years to work a radical change in painting, and their tendency to experiment, apart from style, also with new techniques and materials, places limits on the possibility of determining authenticity by scientific methods. The tendency nowadays is to substitute technical verification with the sole consideration of the painter’s signature. In modern art the privilege of authenticating signatures belongs to experts or groups of experts. But there is an increasingly important opportunity for scientific methods: that of weeding out the numerous copies and fakes by dating the material, thus verifying any incompatibility between the age of the painting and the period in which the painter was active. New methods are constantly increasing the applicable time span, which in many cases now reaches up to the 1920s.


A work of art
is material

prior still to being a message.

  Once finished, it acquires
an individuality of its own, which is a synthesis of the philosophy, sensibility and manual dexterity of its creator.

(M. Hours
former Inspector General 
of the Museums of France)

"Giuditta I"
by Gustav Klimt


A recent copy of
"Giuditta I"


Example of certificate made by the scientific laboratory of the Museum
on a XIX century painting

The Scientific Laboratory  of
Museo d’Arte e Scienza



Results of the scientific tests performed on the painting
on canvas (49 x 60cm) shown in the photo -
with "Sisley" signature -
presumed period: end of the XIX century

The ascertainment of the authenticity of this painting has been carried out with scientific tests on the material and through the study of techniques and signs of wear.
In detail:

1) with the spectroscopic dating of  the wooden stretcher once proved its originality
2) with stereo microscopic analyses for the study of the painting layer: the drying of the paint binder, the craquelure, the sign left by the stretcher, etc.
3) with Wood’s Light and microscope for the examination of restored areas
4)  with IR-Reflectography for the examination of the deepest painting layers
5) with microscope, Wood’s Light and reflectography in order to verify the material uniformity and the ageing of the signature
6) with IR-Spectroscopy for establishing the pigments used and examining the drying of the paint binder

The above tests allowed to state the compatibility of the material, signs of ageing and techniques with the period of the painter’s activity.


See the complete results: click



The scientific laboratory of the Museum

Every attempt to determine the authenticity of a painting must begin with tests and analyses to establish whether the age of the painting and the materials and techniques used are compatible with the presumed date of execution. The objective elements attesting to the authenticity of a work are to be found in a scientific laboratory!

The Museum laboratory’s mission is to improve existing scientific methods and elaborate new methods for the ascertainment of the authenticity of art objects. The laboratory’s instruments and know-how for the determining of authenticity are at the disposal of collectors, art experts, restorers, art galleries and museums. (The staff of the laboratory, who speaks the main European languages, is at your disposal for any explanations).

For more information: Tel. 0039-02-72022488 - Email: info@museoartescienza.com

Tests carried out by the laboratory:

Spectroscopic dating and characterization of wooden objects

Microscopic tests on paintings

Examination of underlying layers using infrared reflectography

Analyses of paint layers with a duroflexometer

Analyses with Wood’s light, UV and IR


FURTHER ANALYSES PERFORMED IN THE LABORATORY: Spectroscopic chemical analyses on pigments, glues, encrustations, patinas, products of corrosion. Scientific, practical and instrumental tests of authenticity on: ivory, amber, archaeological glass, pigments, metals, stones,  carpets, tapestry, prints, books, clocks and watches, china.




Acknowledged value
of the museum’s scientific laboratory and its methods for determining authenticity


Attitudes towards and use of scientific methods are influenced by local laws and customs.

Basis of judgment: the situation in Italy (where the museum is located)

The prime institution for the fight against forgery and imitations is the Guardia di Finanza or Financial Police. The most recent catalogue on the determination of authenticity in art, published by the same in June 2007, contains an exclusive six-page presentation of the scientific laboratory of the Museo d’Arte e Scienza in which its methods for dating paintings, furniture, and objects in ivory and other materials are illustrated in detail and their validity, in effect, endorsed.

Judicial proceedings. The probatory value of the spectroscopic dating method is crucial to the outcome of civil and penal judgments involving the determination of the actual age of art works.
A new Italian bill (26.10.2007) provides for fines and imprisonment for the forging of signatures and other characteristics.

The art market: the percentage of unauthentic art works currently on the market is very high.
As a consequence a section of the trade rejects scientific methods out of economic necessity. Furthermore, when dating tests give negative results, dealers often tend to maintain that it is not the art work that is at fault but the scientific test result, or that the method is unknown.

Art lovers and investors. Copies and fakes will continue to be offered as originals as long as buyers of art refuse to follow the same line of conduct adopted when acquiring other “products”, that is to say insisting on a dependable guarantee of the object’s authenticity as the condition for its purchase. It is senseless to content oneself with the personal opinions of experts alone in this age of technology and science. The art market will become trustworthy only when the art lover becomes a connoisseur and, as envisaged by the law, demands a valid certificate.






The value of expertise on art
in the scientific age


€ 4.500  



€ 5.000.000
Auction of June 18, 2006


In the past, when called on to appraise and attribute a painting, art experts examined only the surface under natural light. A superficial examination of this kind was sufficient, however, because it was artistic style and technique they were looking at.

This way of examining a painting has remained the same to the present day, but the attention is now focused almost exclusively on the painter’s signature. The fact that today, as in the future, it is often impossible to attribute a work to an author with certainty, induces the thought that current art appraisal methods are all to the advantage of the market.

Whilst this type of ascertainment is to the dealers’ advantage, for buyers it could mean the almost total loss of their investment if one day this overemphasis on the signature were considered illogical and mistaken and a more traditional way of attributing art returned to favor.

Today it is already possible to reduce this risk thanks to the dating and scientific analyses of the various component materials of the painting and its support. Any incompatibility between the measured ages and information on the presumed author reveals to the owner, before he seeks an expert opinion, that he has acquired one of the myriad recent copies in circulation.

Scientific methods used for determining the age of antique paintings are now applicable for works dating up to around 1920.



Get further and detailed information from our web site:




Example of the complete certificate

The Scientific Laboratory  of
Museo d’Arte e Scienza


The painting has been studied with microscopic, IR reflectrographic, Wood’s light and FT-IR spectroscopic analyses, to verify its compatibility with the presumed period.

Painting on canvas (49 x 60cm)
"Sisley" signature

The overall state of conservation of the painting is good with the exception of a visible L-shaped tear in the left-hand central area. The canvas also shows some small tears on the edges.
A careful preliminary examination of the edges brought to light the presence of a set of new nails, whilst there are numerous free holes left by preceding nails. It was noted in particular that in the case of the two side strips making up the stretcher there is a perfect correspondence between the holes currently present in the canvas and the holes in the underlying stretcher. Attached please find photos of the two sides with a red arrow showing the holes in the canvas which match those in the stretcher underneath (photos no.2, no.3 and no.4).

   Photo 2

Photo 3 -


Having thus ascertained that at least the two side strips of the stretcher are unquestionably original and coeval with this painting, we proceeded to date them scientifically. The spectroscopic analysis of the wood gave the following results:

Wood type = conifer


Age of the wood = 115 +/- 10 years
(spectra enclosed)



Analysis of the Painting layer

The study of the painted surface, thanks also to the use of a stereo microscope, showed up the following characteristics.

Many areas of the painting evidence a deep, extensive craquelure. The development of the same is also logical: it varies according to the different colours and in particular is more marked in the light-coloured areas which, containing less binder, are also less elastic and the first to develop cracks (macro photos no.5 and no.6).


Photo 5 - deeper craquelure in the light-coloured areas


Photo 6 - craquelure variation according to the different colours

Near the edges on either side of the painting there are also parallel cracks exactly over the inside corner of the underlying stretcher; this is a characteristic typical of a canvas which has been attached to its stretcher for a long time. Moreover, the fact that the position of these cracks corresponds to that of the inside corner of the current stretcher is further confirmation that the side strips are definitely original.
When pressure is applied by a special instrument (durometer) on the paint layer, which is fairly hard as a result of the drying of the paint binder and the colours, it tends to crack rather than warp.
All the above features are typical of an authentic craquelure which has formed naturally and begin to be noticeable about
80-100 years after the date of execution of the painting.


Analysis of the Signature

The microscopic examination of the signature (macro photos no.7, and no.8) evidenced its uniformity with the rest of the painting: it can be seen, in fact, that the colour has worn to the same degree, especially in the more protruding areas, and has not penetrated into the fissures of the craquelure as would have been the case if the signature had been inscribed onto a painted surface that was already old.


Photo 7


Photo 8



Examination under Wood’s light also showed that the reactions of the signature were comparable to those of the rest of the painting (photo no.9 taken under Wood’s light). These observations therefore attest to the fact that the signature is contemporary with the painting.


Total analysis with Wood's light

An overall examination of the painting under Wood’s light showed up a little number of restored areas, particularly to the upper right in correspondence with the sky: in fact under Wood’s light these areas appear as dark patches. They are clearly visible in photo no. 10 taken with the help of specific filters and subsequent digital elaboration.
The IR reflectographic analysis did not evidence any underlying preparatory drawing or other features beneath the painting.


IR Reflectographic Analysis

The analysis in infrared reflectography allows to study the painting in depth obtaining information about possible drawings below the painting surface.

Foto 11 - In this specific case the analysis did not found a preparatory drawing of the subject below, but it pointed out some parallel lines to external edges, which determine a perimetric rectangle.
The attached photo, which shows the lower corner near the signature, points out very well this characteristic (red arrows).



Analysis of the pigments


An FT-IR spectroscopic test was then carried out on a number of areas of colour in order to establish the pigments used.

In particular we studied a surface white, the white preparatory layer and the blue of the river water.

The white used on the surface resulted as being made up of: lead white with barium sulphate and an addition of zinc white;
the preparatory layer, instead, consists of lead white and calcium carbonate,
whilst for the blue colour Prussian blue was used.
(spectra enclosed)

The absence of titanium white, a pigment used only after 1920, was also verified.


The analysis also indicated the small contribution made by the paint binder (peak at 1735 cm-1) pointing to its state of advanced desiccation.



The above observations and the results of the scientific tests give us a series of positive indications of the painting’s natural ageing:

- the result of the age of the stretcher: 115 years
the paint layer which is fairly hard as a result of the drying of the paint binder
- a
 deep, extensive and natural craquelure
- the coherent material of the signature
some parallel lines to external edges underneath the surface usually made by this painter
- the use of coherent pigments
- a little number of restored areas

For these reasons it is possible to attest its compatibility with the spectroscopic dating of the wood of the stretcher. It is also positive that there are no signs of forgery in the painting or in the signature itself and that its apparent age coincides with the last years of life of the painter in question.

To return to the laboratory: click





The following pages propose
 three kinds of tests available
to the owners of paintings
to determine their authenticity on an
objective basis (excluding the artist's name!):


A) - Tests which the owner can carry out in his own home, following the instructions set out here or in the Museum's Handbook.

B) - Scientific tests carried out in the laboratory on samples taken by the owner and mailed to the Museum.

C) - Tests which can be performed only in the laboratory by bringing the object along. (See the first pages)


The examples shown here have been chosen by the laboratory of the Museum of Art and Science to advise or inform the owners of paintings of the numerous possibilities in existence, enabling them to better assess the value of their artefacts.

There are no descriptions of stylistic features, the formal aspects of which have already been treated by an abundance of art books in all languages. These books are, however, attentively read also by forgers who, wanting for instance to specialize in Gothic painting, can not only document themselves on techniques and styles of the period, but gain even more information than an artist or craftsman living at that time on the materials used and on the overall cultural context.



The texts and photos of this website are extracts from "The Art Collector's Handbook"
3 volumes in three languages, published by the "Museum of Art and Science"





Visual tests with the aid of a magnifying glass (1:10).
The three most significant examples have been chosen from among the numerous available

1 - Craquelure

One of the most reliable clues to distinguishing old from new is offered by the network of cracks that develops over time in the paint layer (craquelure). This is caused almost exclusively by deformations in the painting's wooden or canvas support.

The canvas of a painting easily
 gets bent around the inner
border of its wooden stretcher,
causing the first cracks to develop
parallel to the stretcher (a).
Cracks that form also above the stretcher (b) 
have probably been created artificially.


In oil paintings cracks usually form
after 60 to 120 years.
They make their first appearance
in the whites.
This characteristic provides one of
 the few possibilities  of establishing
the authenticity of works created by the
great painters active around 1900
such as Cézanne, Gauguin
 Van Gogh and others.


panel paintings
As the structure of the wood
 consists of long parallel fibres,
the swelling and shrinking of the support
as a result of humidity and heat
cause the surface to crack
 initially along the wood grain.



2 - Pigments

Most of the pigments used until the start of the 19th century were obtained from minerals, natural metal oxides, earths of various colours and a small number of vegetable colourants.


The size of the grains of pigments
is also of decisive importance for determining
whether they are "antique" or "recent".
Visible grains are proof that
the colours were ground by hand.


Since a colour's hiding power increases,
the smaller the size of the grains,
industrial pigments are ground
 as finely as possible
Grains which are almost invisible in
a painting may be an indication that
 it is of recent production.


Many yellow pigments are
 unstable and sensitive to light.
Therefore, bright yellow in an
antique painting should draw
careful scrutiny. Yellow pigments
mixed with blue often serve to
 produce green. This is why green
hues are seldom vivid and tend
 to turn a nondescript
greenish brown.




3 - Patinas and protective varnishes

The outer layer of paint in
antique paintings undergoes
 severe chemical and physical
 change over the centuries.
For this reason antique paintings
were covered with a protective coat of
transparent varnish.
 In the absence of this varnish
the surface would look grey.
This grey veil, if present, is an
unfakable indication that the
 painting is antique.
It becomes visible if the protective
 varnish is removed with
cotton wool soaked in alcohol
(for test purposes clean only
a small area near the edge).


If the same test is carried out on
 a recent copy, fresh and industrial
colours re-emerge. The alcohol
test, preferably performed by a
restorer, causes no damage.

The most commonly-used method
for ageing a surface is to spray it with
a dark-coloured liquid.
 The uniformity of the marks thus obtained
differs from the myriad of tiny dark
lumps deposited over time.



B)  scientific
examinations on samples of material taken by the owner and analysed by a laboratory.

   The purpose of analyses effected on samples taken from paintings is to investigate the following factors:


Determination of the type of material and distinction between natural and synthetic.


Comparison between the age of the material present in the painting and the date of introduction and utilization of the same in painting.


Absolute dating of the wood used as support or stretcher.

Modern technology, applied by experts, allows the certain distinction between an antique painting and a relatively recent copy of the same,  but does not permit an original antique painting to be distinguished from a copy of the same age.
In order to know the name of the artist it is necessary to have the historical documentation of the painting appraised by a serious expert.

   Instructions on how to take samples of material






Panel paintings: gather a few mg of wood dust both from the surface and in depth from the rear of the panel, following the instructions provided in our website www.spectroscopyforart.com. The sample taken from the surface permits exclusion of the use of wood that was already old. The results of the analysis establish the age of the wood with certainty.
Paintings mounted on wood stretchers: Carry out the above tests after ascertaining that the stretcher is original.


Pigments, binders in general and canvas: Remove a piece of canvas of the size of about 1 cm² bearing remains of paint (see drawing).


Specific pigments (whites, blues, yellows and greens):
Using a thin blade, remove about one mm² of the paint layer from an unimportant area of the painting.  

     The results of tests II and III give the verdict: “compatible” or “incompatible” with the presumed age




C) specific tests carried out by the laboratory of the museum of art and science

Thanks to the laboratory's modern equipment, a painting can be subjected to analysis using infrared reflectography, Wood's light, a stereoscopic microscope, IR spectroscopy and other instrumental techniques.

Microscopic analysis
to examine the signs of ageing in the paint layer: the nature of the craquelure (natural or artificial - deep or superficial), the pigments (crystallinity,  purity and size), restoration and other factors.

 examination of craquelure

analysis of pigments



Wood's light and monochromatic lights permit an evaluation of the extent to which the painting has been restored, touched up and overpainted, as well as the identification of various fluorescent substances.

restoration work shown up

stucco work identified



Infrared reflectography permits an in-depth examination of the painting bringing to light underdrawings or grids, pentimenti, and the depth of the craquelure, and identification of restoration work or the use of different materials.

depth of craquelure

 underlying grid





IR spectroscopic analysis permits the analysis of various materials to ascertain their compatibility with the presumed historic period: pigments, binders, glues and varnishes. Minimal sample quantities needed.

sample to be analysed enclosed in a KBr pellet


insertion of sample in the spectrophotometer




IR spectroscopic
dating of wood
for further information on
the dating of a painting's stretcher, support or frame
please visit our website www.spectroscopyforart.com

spectroscopic analysis unit


dating spectrum




Evaluation of the
 physical properties
 of the material
measurement of the dessication of the binder and the elasticity of the paint layer

analysis with duroflexometer


measurement of surface elasticity


The laboratory also digitalizes images obtained by the various techniques, carries out examinations under reflected and raking light, and performs microchemical analyses.
Certificates are issued with a clear and exhaustive report on the results of the analyses.



Graphic Art and Prints

Sheets of paper coloured by mechanized systems for mass production are hard to define as works of art. Furthermore, in the case of signed items sold at relatively high prices, the risk that they are not authentic is also very high.

Let us take for example the most widely sold and esteemed graphic artist: Salvador Dalì.
It is estimated that of the Dalì prints available today on the market, hundreds of thousands of all of them, are fakes. And the chief faker was Dalì himself. The facts are well known.
There is no typical signature of Dalì in the field of his graphic work. Only the fraudulent signatures are consistently repeated.

The attempt to ascertain the authenticity of a print is fruitless.





Icons were painted in cloisters by nuns and monks as a testimony to their faith and devotion. The icon painter tries to impart a transcendent spirit to the painting by praying at length and fasting as he creates the image. To reach this objective the faces are painted in different layers of colour, each coat of which is left to dry before the next is added, thus leaving the artist-monk long intervals to spend in prayer.

The main clue to distinguishing authentic icons from faked ones at first sight is the stratification of the paint on the faces, which appear almost in relief if observed under a raking light (see Collector's Handbook pp. 65-76)

For all other investigations, what has been said for panel paintings holds good also for icons.




The Founders and the staff
of the Museo d’Arte e Scienza


Gottfried Matthaes
Founder and  President

Giovanna Cozzi Matthaes


Dott. Chim. Peter Matthaes
Lab. Director and CTU

Patrizia Matthaes
Silvia Mayer
Language and Communication
Dr. Martin Matthaes
Chiara Civardi
First lab assistant
Roberta Delmoro
Art Historian (Freelance)
Marta Cugnasca
Data processing
Sonia  Checchini




Branch of the Milan scientific laboratory for determining the authenticity
of valuable antique art objects


Other requests may be sent, as always, directly to the Milan laboratory at the following address:

Museo d’Arte e Scienza
Via Q. Sella 4 – 20121 Milano
Tel. 0039 02 72022488
Fax 0039 02 72023156
e-mail: info@museoartescienza.com




With this guide to detecting fakes, you will always have a trusted expert by your side, ready to provide you with clear and straightforward answers as to the authenticity and originality of the items that arouse your interest.

Title: THE ART COLLECTOR'S ILLUSTRATED HANDBOOK (three volumes - three languages)

The Author, Gottfried Matthaes, a physicist, was born in Germany of a family of longstanding artistic tradition and since 1960 has dedicated himself to the study of practical and scientific methods for the ascertainment of authenticity. In 1990 he founded the "Museo d'Arte e Scienza", the only one of its kind in the world, in the centre of Milan where most of the objects illustrated in the handbooks are exhibited, together with its attached laboratory. In 1993 he discovered and patented the application of IR spectroscopy for the age dating of wooden art objects.

VOLUME 1: Ivory, Paintings, Icons, Carpets and Rugs, Tapestry, Furniture, Glass, Ceramics, Scientific Methods
VOLUME 2: Paper, Books, Prints, Metals, Clocks, Walking Sticks, Pipes, Musical Instruments, Precious Stones, Amber, Pearls, Enamel Paint, Dolls, Toys, Fans
VOLUME 3: Minor Asian Arts, Excavated objects, Buddhist Art, African Art, Indonesian Art
Price: Volume 1 (278 pages) 40.00 Euro
Volume 2 (128 pages) 30.00 Euro
Volume 3 (128 pages) 30.00 Euro
Shipping charges are not included .
International Code:

Volume 1 - 1997, Code ISBN 978-88-900454-5-5
Volume 2 - 1999, Code ISBN
Volume 3 - 2000, Code ISBN

How to buy it:
  • in all bookshops giving the above mentioned ISBN code number
  • directly at the Art and Science Museum (with discount)
  • by e-mail



Examples of pages taken from volume 1



 Vol. I

      Subject:  PAINTINGS and ICONS   Total pages on subject: 92  Illustrations: 207

      Pages 18 and 22, Chapter  Craquelure - 26, Chapter Fake craquelures

    Page 48, Chapter Copies: kind and value

Sample pages




 vol. I

      Subject: PAINTINGS and ICONS   Total pages on subject: 92  Illustrations: 207

       Page 67,  Chapter Faces        Page 70, Chapter Icon oklads

       Page 84,   Chapter Reflectography          Page 86, Chapter Infrared rays

Sample Pages





www.MuseoArteScienza.com - Sections of the "Museo d'Arte e Scienza": 6 rooms dedicated to the ascertainment of authenticity in art and antiques, 5 rooms about The "Treatise on Painting" of Leonardo Da Vinci and Leonardo's activities in Milan, 5 rooms dedicated to African Art and Buddhist Art, 2 Scientific Laboratories.

www.LeonardoDaVinciMilano.com - two permanent exhibitions: "Leonardo Citizen of Milan" and  "Appreciating Art through the Eyes of Leonardo" from his "Treatise on Painting".

www.AuthenticAfricanBronzesandCeramics.com -  dedicated to the authenticity of African artworks in bronze, stone and pottery. The scientific laboratory of the Museo d’Arte e Scienza has developed valid methods for telling authentic African objects from copies and fakes.

www.ArtAndScienceHandbook.com - The most complete and scientifically valid guide to ascertaining the authenticity of European and non-European antiques on an objective basis (540 pages and more than 2000 colour illustrations in 3 volumes and 3 languages)

www.AntiqueFurnitureAuthenticity.com - A list of possible methods for determining the authenticity of furniture based on objective factors.

www.Excavatedartauthenticity.com - "A list of all the possible ways of determining, on the basis of objective factors,  the authenticity of excavated pottery, glass or bronze items from Southern Italy, the Mediterranean Basin, China and South America.".

www.AfricanArtAuthenticity.com - "Art and Life in Black Africa", The African Art didactic section of the Museum (5 rooms and over 350 objects).  

www.SpectroscopyforArt.com - Scientific method for the dating of the wood and identification of the wood type used for art objects. Determination of their authenticity through analysis of colours, binders, pigments and other organic substances.  

www.Matthaes.org  - The history of the G. Matthaes Foundation from the opening of the painting school in Dresden in 1906 up to the Museum "Arte e Scienza" in Milan.

www.CopiesAndFakesInArt.com - Ample further descriptions for ascertaining the authenticity in art for the individual fields of antiques.

www.Ivoryauthenticityandage.com - Ivory, bones and horns can now be spectroscopically dated and recognized with precision.

www.LeonardoTeacherofPaintinginMilan.com - An abridged and illustrated edition of the “Treatise on Painting”.