infinitely many pairs $$\label{layered}
\omega(x_1)=\pi\sum\limits_{j=1}^{\infty}\zeta(\mu_j,x_1-a_j)\zeta(\mu_{j+1},-x_1-a_{j+1})$$ gives a layered topological charge structure in $R^4$, Fig.\[Fig:layered\].

Formally, one may try to go further and consider the product $$\label{asd_lump}
\omega(x)=\pi\prod_{i=1}^k \zeta(\mu_i,\eta_\nu^{i}x_\nu-q^{i}).$$ For an appropriate choice of normal vectors $\eta^i$ this superposition represents a lump of anti-self-dual field in the background of the self-dual one, in two, three and four dimensions for $k=4,6,8$, respectively. The case $k=8$ is illustrated in Fig.\[Fig:asd\_lump\]. The general kink network is then given by the additive superposition of lumps (\[asd\_lump\]) $$\label{kink_network}
\omega=\pi\sum_{j=1}^{\infty}\prod_{i=1}^k \zeta(\mu_{ij},\eta_\nu^{ij}x_\nu-q^{ij}).$$ The correponding topological charge density is shown in Fig. \[Fig:kink\_network\]. This figure as well as the LHS of Fig. \[Fig:layered\] represents the configuration with infinitely thin domain wall defects, that is the Abelian homogeneous (anti-)self-dual field almost everywhere in $R^4$ characterized by the nonzero absolute value of the topological charge density which is constant and proportional to the value of the action density almost everywhere.

The most RHS plots in Figs. \[Fig:layered\] and \[Fig:kink\_network\] show the opposite case of the network composed of very thick kinks. Green color corresponds to the gauge field with an infinitesimally small topological charge density. Study of the spectrum of colorless and color charged fluctuations indicates that the LHS configuration is 