One of the likeable sides of Helmantel is his strict rationality in his profession. Does this stand in contrast to his Reformed protestant religious convictions? Not at all. Consistent mono-theism leaves no room for superstition. The effect in this case is very favourable, since most realistic painters think that the Old Masters had better materials than we do. That is not true. Apart from linseed oil, almost all the materials which they used were more unreliable than ours, and only the collective professional experience of generations was able to save them from disasters.