ΔE 6.5, close: similar, with a visible difference side by side. Rust is a little lighter than Skin INK. They are different kinds of paint: AK Interactive Skin INK is an ink, glaze or transparent paint and Army Painter Rust is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Rust is a little lighter than Skin INK. They are different kinds of paint.
The same difference applies the other way round: Skin INK is a little darker.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Skin INK on the colour wheel See Rust on the colour wheel
All matches: Skin INK equivalents · Rust equivalents