Immaterial vs Insubstantial - What's the difference?

As adjectives the difference between immaterial and insubstantial

is that immaterial is having no matter or substance while insubstantial is lacking substance; not real or strong.

(en adjective)

Having no matter or substance.

Because ghosts are immaterial , they can pass through walls.

Irrelevant.

Objection, Your Honour! The defendant's criminal record is immaterial to this case.

* material

(en adjective)

Lacking substance; not real or strong.

The bridge was insubstantial and would not safely carry a car.

* unsubstantial (archaic)

* substantial