Netherlands Institute for Conservation, Art and Science

NICAS Colloquium

23May2019 12:00 - 13:00


The next edition of the NICAS Colloquium takes place on Thursday, 23 May 2019, from 12:00 to 13:00 in Conference Room B of the Atelier Building (Hobbemastraat 22, Amsterdam).


The chair of this colloquium will be Joen Hermans (Rijksmuseum/University of Amsterdam).


The following presentations are scheduled for this edition of the NICAS Colloquium:


Optomechanical ferrule-top nanoindentation as a new tool to study crack pattern formation in paintings

Mathilde Tiennot

Craquelure patterns in paintings result from stresses induced by the differences in mechanical behaviour of layers within the paint stratigraphy. This may be triggered by the paint/ground composition, drying process, environmental changes, and physical impact. To address this, the heterogeneous viscoelastic properties of composite layers, as well as their adhesion at the interface are studied. To investigate the mechanical and fracture behaviour of the paintings layers at local scale, a specific nanoindentation protocol using a micromachined ferrule-top probe is developed. The method has been designed to enable mechanical mapping of paint cross-sections and is used to evaluate the viscoelastic properties of paint layers and of their build-ups. Two 17th-century Rijksmuseum paintings by J.B.Weenix, both unlined, on their original stretcher and showing extensive cracking and delamination, are considered as case studies.

Mathilde Tiennot (VU University/Rijksmuseum) is a postdoctoral researcher at the Rijksmuseum and the Vrije Universiteit, where she is developing a new nanoindentation protocol to evaluate the micro-mechanics of cracks in paintings.


Dryer despite itself? The role of zinc sulfate in fifteenth century oil painting

Indra Kneepkens

Sources and analytical results suggest that zinc sulfate was a common additive in late medieval oil paints. Although technical recipes refer to it as a dryer that was added to the oil or directly to the paint, attempts to reconstruct a siccative effect have so far been unsuccessful. The idea was proposed that the drying effect of historical zinc sulfates was unknowingly caused by associated trace materials, such as manganese, which lack in modern zinc sulfates. In this study I compare the composition of several modern and historical zinc sulfates as well as their effects on the handling properties and drying time of paints, depending on the way they are applied. With these experiments insights are gained about role of zinc sulfate in fifteenth century painting technique and the relation between art technological sources and historical practice.

Indra Kneepkens (University of Amsterdam) has a master’s in art history from the University of Amsterdam and is currently finalizing her PhD at the same university. Her thesis is about the role of processed linseed oils and paint additives in late medieval panel painting.



Thursday, 23 May 2019


12:00 – 13:00 hrs


Conference Room B, Atelier Building
Hobbemastraat 22, Amsterdam

Published by  NICAS