White Precision Base vs Wrack White

How close are they?

ΔE 7.7, close: similar, with a visible difference side by side. Wrack White is a little darker, more saturated than White Precision Base.

Can I use Wrack White instead of White Precision Base?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Wrack White is a little darker, more saturated than White Precision Base.

Can I use White Precision Base instead of Wrack White?

The same difference applies the other way round: White Precision Base is a little lighter, more muted.

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.