Fig. 3From: The influence of heartwood, sapwood and density on moisture fluctuations and crack formations of coated Norway spruce in outdoor exposureMC fluctuation over 3 years for the film-forming coatings (average of A, B and C) categorised by high- or low-density heartwood or sapwood. The error bars represent the standard deviation of the values. The climate data during the period are given in Fig. 1bBack to article page