ΔE 5.3, very close: most people won’t see a difference side by side. Brown Ink is a little darker than Sepia Tone. They are different kinds of paint: Army Painter Sepia Tone is a wash/shade and Reaper Brown Ink is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Yes, for most jobs. Very close match (ΔE 5). Brown Ink is a little darker than Sepia Tone. They are different kinds of paint.
The same difference applies the other way round: Sepia Tone is a little lighter.
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 Sepia Tone on the colour wheel See Brown Ink on the colour wheel
All matches: Sepia Tone equivalents · Brown Ink equivalents