We use simulation and analytic modelling to probe the structural similarity reported in the literature for ﬁbre networks with manifestly different degrees of uniformity. From simulations of point processes in the plane to represent random, clustered and disperse ﬁbre centres, we show that the distribution of distances between pairs of centres is very insensitive to the extent of clustering. Further, we quantify the correlation between the lengths of adjacent polygon sides arising from a Poisson line process in the plane as being ρ = 0.616 ± 0.001 and show that this is very insensitive to ﬁbre orientation and only weakly inﬂuenced by clustering. The relevance of this correlation to pore geometry is discussed.
In the ﬁnal part we analyze simulated areal density maps and show that their variance relative to that of a random ﬁbre network of the same constituent ﬁbres, as quantiﬁed by the formation number, depends at small scales on the ﬂocculation intensity only and depends at large scales on the number of ﬁbres per ﬂoc only.