Carbon-14 Dating Method

Carbon-14 Dating for the Paper Support of Paintings by T'ang Haywen or Allegedly by T'ang Haywen

Following requests for authentication from several buyers of paintings presented as authentic works by T'ang Haywen — and given that many of these paintings exhibited significant flaws — T'ang Haywen Archives decided, as a first step, to conduct Carbon-14 dating on a total of 20 paintings to scientifically determine their dates of creation.

• 14 of these works bore false signatures and demonstrated improper brush handling, resulting in dull and lifeless compositions.

• To establish a reference for comparison, the T'ang Haywen Archives also dated 6 works of undeniable provenance, i.e., undeniably authentic works by T'ang Haywen. These paintings are diptychs, executed in ink and/or watercolor on Arches paper, and thus likely belong to the final period of T'ang's oeuvre.

  
  

The task of dating the works was entrusted to the Laboratory of Ion Beam Physics at the Swiss Federal Institute of Technology (ETH Zurich).

Understanding Carbon-14 Dating Results

Carbon-14 dating produces both a rising date and a descending date, which appear on a curve. The descending date is of particular interest here, as it indicates when the fibers of the paper were harvested. In these cases, the fibers are cotton, and the absorption of Carbon-14 by the cotton plant ceased at the time of harvest — essentially, at the moment of the plant's death.

Key Findings

The results are conclusive:

• The descending dates for the 14 paintings with false signatures fall between 2008 and 2011. This means the paper was made from fibers harvested 17 to 20 years after the artist's death (T'ang Haywen passed away in 1991). These paintings are therefore confirmed to be fakes, produced at least 17 years posthumously.

• The descending dates for the 6 paintings of undeniable provenance range from 1986 to 1990, placing the fiber harvest 1 to 5 years before the artist's death. This further confirms their authenticity.

Certificates and Comparisons

Below, you can review some of the certificates issued by the ETH Zurich Laboratory. Additionally, you can compare and evaluate the differences between fake and authentic signatures, as well as the stylistic distinctions between fake and genuine works.

In the attached PDF file, you will find:

1.    Examples of Carbon-14 certificates for works painted on paper made with fibers harvested 17 to 20 years after T'ang Haywen's death.

2.    Carbon-14 certificates for works painted on paper made with fibers harvested 1 to 5 years before T'ang Haywen's death.

3.    A chart comparing the 14 signatures of works produced by the forger(s) after the artist's death and the 6 signatures of works created by T'ang Haywen during his lifetime