The Ploug Authenticity Research

General

Based on a protocol including the technical details and settings of the measurement-instrument and the visualization of the measurement-spots (to ensure a permanent possibility for a repeating of the measurement), the elements found in artworks can be quantified and qualified. The results produced by Bruker Xrf ARTAXTM Helium 800 are non-destructive, visualized, and reproducible.[1] This way the measurement-spots are kept intact for a possible ‘counterfeit checking’. This possibility was offered to Cor van L. and his lawyer during legal proceedings, however, they did not use this opportunity for a counterfeit check. Of course, A.R.R.S. would have been more than willing to repeat the process in front of two notaries or representatives of the court.

In this research on the authenticity of the doubtful works were included: two original works by Jan Altink, two doubtful works possibly made by Jan Altink, two doubtful works possibly made by Johan Dijkstra, and one original work by Cor van L. All four doubtful works were bought from Van L. The painting made by Van L., which serves as a point of reference within the problem definition, was sold by Van L. to Meijering as an original. The original Altinks stem from different private collections.

Time and again Van L. tries to create confusion by referring to the binders used for the paintings. The binders, however, do not constitute irrefutable evidence in this research. The mixture of paint pigments and the siccatives, on the other hand, does. For this reason, the A.R.R.S.-research focused on paint pigments, siccatives, and paint application.

[1] Pinna, Daniela (ed.). Scientific Examination for the Investigation of Paintings: A Handbook for Conservator-Restorers. Florence: Centro Di. 2009, page 210-213.

The Grounding

The measurements regarding the grounding are particularly relevant to the conclusion, as it is based on one working method and one application, namely the manipulation of the drying process of the material. The use of active and surplus dryers (siccatives) in the grounding and the first paint-layers on the grounding, points towards a deliberate manipulation of the end-result of the painting: the forming of artificial craquelures. This process is very much contrary to the natural development of craquelures through aging.

The application of the three different white pigments (zinc-, lead- and titanium-white) in the grounding of a painting affects the durability of a painting. In particular, the addition of titanium-white to zinc-white is contra-productive to the drying process. As a result, a quick-dryer, or siccative, needs to be added. The addition of these quick-drying siccatives to the mixture of the three pigments only serves one goal: influencing the drying process in such a way that an active shrinkage and expansion is created. The shrinkage and expansion of the ground layer is necessary to create a so-called ‘natural-looking’ craquelure pattern in a short period of time.

Experts, basing their opinions on the naked eye, use these ‘natural-looking’ craquelures as an indication of age, and therefore as an indication of authenticity.

The origninal works by Jan Altink

The original works of Altink have no (0%) relationship with the abovementioned mixture-technique of paint and siccatives in the grounding. A traditionally schooled painter such as Altink would have been consciously aware of the negative behavior of this grounding.

Artists that want their paintings to be durable will always avoid this process of mixing and drying. It is therefore no surprise that in the original works by Altink this working method hasn’t been detected.

Paint-layers

Indicative is that this phenomenon of paint-mixing and forced drying cannot only be detected in the grounding, but also in the top layer of the painting. This is most likely a characteristic of the painter. The top layers of the doubtful works and the work by Van L. show a similarity in working method and materials. Taking into accord the measurements of the doubtful Altinks, a remarkable match can be detected. The paint and technique of these works show a 100% match with the original work of Van L., and a 0% match with the original Altink.