Case: Monet

RECENART’s mobile laboratory team visited Serlachius Museums to study some of their paintings. One of the paintings was Monet´s painting Haystack in the evening sun from 1891. The painting did not have a visible signature.

With hyperspectral imaging the Monet signature was found underneath the paint layers. Also the pigment analysis made with XRF-spectrometer confirmed that the pigments are suited to Monet´s production. The painting has been owned by Gösta Serlachius Fine Arts Foundation since the 1950’s but it has not been researched before. The Monet´s painting was one of the first paintings to be researched and the surprise was great among the museum personnel and the research team, when the Claude Monet´s signature was revealed.

Monet signature revealed
Monet signature revealed
Monet HaystacksMonet Haystacks


Case: Medieval wooden retable

RECENART team visited in Jämsä to study an old retable from the 15th century. The retable is extremely well preserved. The team used non-destructive methods and did the whole sampling on site.

A portable XRF-spectrometer was used to carry out the pigment analysis of a late medieval wooden polychrome retable. The task was to determine a precise date for the object. The XRF-analysis indicated the presence of lead and tin in the yellow color areas. In the late medieval era there were two types (type I and II) of lead-tin yellows available for artists.

Further analysis with SEM-EDS and polarized light microscopy proved the pigment as type I and this dates the retable to post 1450 AD.


Case: Halonen

In the landscape painting of the beloved Finnish artist Pekka Halonen (1865-1933), the Finnish lake is presented in misty Winter day.  Water is covering the icy lake – the Spring is coming.

The hyperspectral image of the same painting tells another story. The icy lake is covering a handsome gentleman with a convincing sideburns. Science may reveal over hundreds of years what the artist has been thinking when painting an artwork.

The lake landscape was painted on top of a portrait of a gentleman. Up left is the image in normal light, on the right is traditional IR-image. Below hyperspectral images processed with two different spectral parameters are presented.

Why is the portrait covered? Was the artist dissatisfied with his work? Was it so that the model decided not to buy the artwork after all, and Halonen re-used the fabric again? In this case, the quality of the hyperspectral data reconstruction is so good that the man in the canvas could easily be even recognised, if an art historian would like to make a deeper study of the history of this painting.

The hyperspectral cameras enable RECENART scientists to analyse artistic process, underdrawings, possible earlier paintings and vanished signatures. Ultimately, also the individual pigments can be identified from the spectral data, which is important when dating the artwork. No other technology can provide such combination of valuable information as hyperspectral imaging analysis.


The alleged Frans Hals was bought to a private collection in 1930s. The IR-image did not reveal the still-life painting underneath. After hyperspectral imaging the still-life with flowers was seen clearly. The painting is a forgery and painted on top of an old painting. The material analysis revealed the pigments were not in use in Frans Hals era.