Technological Limitations

	This section profiles the limitations of the two mission critical technologies that are currently in use by the Veritus sponsored artist research committees. These two technologies were used to provide all attributions listed at this web site. Other supporting technologies were also used to verify most results, primarily x-ray technologies, chemical analysis and certain dating technologies. Veritus is working diligently to overcome the limitations of existing technologies.
Digital Colour Palette Analysis
"...paintings from close to the same period of time often have nearly identical base colour palettes."	This technology has proven a very promising support tool in the determination of authorship. Colour usage has long been a important tool of the expert in determining the attribution. However, until the development of this technology all decisions made about colour pallet used by individual artists were subjective and not analytical. The Colour Palette Analysis programme makes a careful evaluation of the exact colours used in various paintings, particularly in those pigments that are not fully mixed. This analysis becomes extremely important when determining attributions, as the colour palette used by an artist normally evolves slowly as the artist uses up a particular paint or incorporates new colour ideas. Artists also experiment with different colour combinations and these can be tracked through a series of paintings. Consequently, paintings from close to the same period of time often have nearly identical base colour palettes. An example of this is the Young Christ in the Temple which was painted concurrently with The Anatomy Lesson of Doctor Tulp. The base colour palettes are nearly identical. The application of this technology then, also, becomes not only a valuable tool for determining who painted a work but, also, for determining when it was painted. A more complete description of the technology is found in the section that deals with technologies used for attribution. It is the opinion of the various artist research committees and Veritus that this technology is inconclusive when used as a standalone procedure. No Veritus sponsored committee used this technology alone to provide for the attribution of any painting. However the committees have used this technology to verify the dating of some works and to identify some studio works. The main limitation of this technology is that it is always inconclusive when used as a stand alone technology. It is considered by all Veritus sponsored committees to be inconclusive because is possible that a different artist in a studio could have used someone else's pallet. The master himself may have done some painting on a studio painting which was then touched up by another artist. This touching up may have removed the Master's brush strokes but not the colours, therefore his signature colours appear. Additionally, some students used very similar colours and the palettes were not always consistent. Because the range of the human eye is somewhat limited in colour perception, an artist can think he is using the same colour when he is actually using a slightly different colour. Therefore, the various committees use this technology as a tool for the confirmation of other evidence but not as a stand alone method of determining attributions.
Digital Brushstroke Analysis
"...detect when the same paintbrush was used on more than one painting."	This technology became our mission critical programme. It has proven to be often as identifying as a fingerprint. The technology allows for comparisons of key features and nuances consistently appearing in individual brushstrokes. When very large numbers of brushstrokes are compared, definitive patterns emerge. The computer effects these brushstroke comparisons at a rate of thousands of comparisons per second. It learns as its data base increases. The sophistication of this technology makes it possible to detect, on occasion, when the same paintbrush was used on more than one painting. It is a little like the forensic examination of a bullet. Some bristles leave distinctive patterns that are reproduced on more than one painting. Although this technology is used primarily to determine who painted the picture, it can, additionally, be employed to provide an indication of relative timing. For example, if the same brush is used to paint two different paintings but there is a marker bristle missing in one of the paintings, that painting would have been painted second. Bristles can be lost from brushes but cannot be replaced. An example of this is the Young Christ in the Temple which was painted concurrently with The Anatomy Lesson of Doctor Tulp. One of the brushes used on Doctor Tulp lost a bristle before being used on the Young Christ in the Temple. It has proven to be often as identifying as a fingerprint. A more complete description of the technology is found in the section that deals with technologies used for attribution. A key limitation of this technology involves building of the database. If there are several well-documented paintings that are absolutely unquestioned as to attribution, they can be used to develop the data base. Once the database is begun, other paintings will emerge as being of the same hand. The data from these works then becomes a part of the database as well. The more that we learn of an artist, the more reliably we can make attributions. There are absolutely no problems with the paintings of the well known artists. However, when no reliable paintings remain in the name of an artist it becomes impossible build a reliable database for attribution. Unfortunately, this is the case with many minor artists. Many unidentified paintings were examined. It is fairly certain that many of these paintings were the work of students in the Rembrandt studio because of the contributions of other technologies. However, so few paintings remain to some of his students that it is impossible to build a meaningful database to provide attribution. As an example, there are no reliable works remaining under the name of the artist Constantin Renesse. He worked in the Rembrandt Studio ca. 1649. He was a painter, engraver and an etcher. There are still a large number of etchings under his name. Several works are claimed to be by his hand but without great confidence. One is a very fine oil work in Austria, once it was attributed to Rembrandt, then it was reattributed to Vermeer, then it was reattributed to Renesse. It is unlikely that there will ever be a sufficient database to conclusively identify the work of this artist. Certainly it is possible that some of the unidentified works could have been by the hand of Renesse. However, Veritus believes it unlikely that it will ever be able to positively identify the works of some of the minor artists in the Baroque period. An additional limitation of the technology concerns paintings that are badly damaged or over-painted. At present, we are not able to obtain precise enough images for our purposes from radiation technologies. Therefore, it is not possible to reliably authenticate in areas that have been over-painted. A number of painting were so severely damaged, restored and over-painted that were unable to identify the artist who painted the work in the main. New technologies are emerging in the area of bio-medical sciences that may provide us with the ability to observe precisely the brushstrokes that lie below the surface. Veritus believes that it will be possible within ten years to properly attribute many of the badly damaged and over-painted works. Some of these paintings may well be of the hand of the master. Finally, some surface textures to not provide adequate information for our third generation technology to make authoritative attributions. For example, the painting attributed to Caravaggio on the ceiling at Villa Boncompagni Ludovisi is impossible for us to verify at this time. However, we expect that this problem may be overcome in the near future.
"...once it was attributed to Rembrandt, then it was reattributed to Vermeer, then it was reattributed to Renesse."
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