s are mind-independent properties. But today we know that perceived and sensed colours exist only in the eye of the beholder. Therefore, the objection ends, I have shown nothing whatsoever about mind-independent patterns, not even their existence. Of course I think that this objection fails and I will, at the same time as I explain why, also defend the following representation thesis: 6. Mind-independent spatial patterns can be represented by mind-dependent spatial patterns. I will not discuss realism in general, only realism for property patterns. This means that I take it for granted that some of the properties which physics talks about do exist in a mind-independent world. Density (=mass density), charge density, and electromagnetic field strength are three such properties which can constitute property patterns. The first two are scalar quantities whereas the third is a vector quantity. There are scalar as well as vector patterns, although I will reason only about scalar quantities. In order to realise that densities-with-shapes and density patterns can be understood realistically, one has to grasp a distinction between real and nominal density. On the one hand there is the real density of each compact and homogeneous part of a body with mass, on the other hand there is the (nominal) mean value density. In homogeneous things the two densities are numerically identical; in heterogeneous things the mean value density always differs from the real density of at least some parts. Mean value density is merely a conceptual construct. It has to be conceived nominalistically. Real density, however, can be conceived as realistically as mass can. As a moving body has in each instant a velocity, a body with mass has in each spatial point a density. A specific colour hue instance is extended in space until it "meets" an instance of another colour hue, or reaches the end of the thing it inheres in. Similarly, a specific real density instance is extended in space until it "meets" an instance of another specific real density,