Sooty Black INK vs Ink Red

How close are they?

ΔE 62.5, loose: different enough that you should pick on purpose. Ink Red is much more saturated, warmer than Sooty Black INK.

Can I use Ink Red instead of Sooty Black INK?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 62). Ink Red is much more saturated, warmer than Sooty Black INK.

Can I use Sooty Black INK instead of Ink Red?

The same difference applies the other way round: Sooty Black INK is much more muted, cooler.

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.