Difference between Insubstantial and Flimsy

INSUBSTANTIAL vs FLIMSY: NOUN

A thin strong light-weight translucent paper used especially for making carbon copies
Thin paper usually used to make multiple copies.
Something written on this thin paper.
A thin sort of paper by means of which several copies of a writing may be made at once; transfer-paper.
A bank-note, from its being made of thin paper.
A manifold copy of a report or despatch made on flimsy; reporters' ‘copy’; a duplicate or a triplicate writing made on flimsy.
Thin or transfer paper.
A bank note.
Thin typing paper used to make multiple copies.
Skimpy underwear.

Having little substance or significance
Lacking solidity or strength
Lacking solidity or strength; easily damaged: : fragile.
Very thin and insubstantial
Resembling cardboard especially in flimsiness
Light, thin, and insubstantial.
Lacking plausibility; unconvincing.
Weak; feeble; limp; slight; vain; without strength or solidity; of loose and unsubstantial structure; without reason or plausibility.
Likely to bend or break under pressure; weak, shaky, flexible, or fragile.
Lacking substance or significance
Not convincing

Without material strength or solid substance; of loose and unsubstantial structure.
Without strength or force of any kind; weak; ineffectual: as, a flimsy argument.
Synonyms Unsubstantial, thin, slight.
Feeble, trivial, shallow, superficial, frivolous, foolish, puerile.
A fragile claim to fame"

Trifling, Vacuous, Flimsy, Insignificant, Aery, Aeriform, Aerial, Unwholesome, Shadowy, Wraithlike, Airy, Unreal, Ethereal, Jejune, Unsubstantial

Feeble, Spurious, Flawed, Shoddy, Unconvincing, Insubstantial, Slight, Light, Onionskin, Inferior, Fragile, Cardboard, Tenuous, Weak, Thin

Trifling, Vacuous, Flimsy, Insignificant, Aery, Aeriform, Aerial, Unwholesome, Shadowy, Wraithlike, Airy, Unreal, Ethereal, Jejune, Unsubstantial

Feeble, Spurious, Flawed, Shoddy, Unconvincing, Insubstantial, Slight, Light, Onionskin, Inferior, Fragile, Cardboard, Tenuous, Weak, Thin

Nothing insubstantial stays put, neither people nor physical objects.
IRS burden associated with redacting such information are insubstantial.
The characters from Hell are also airy and insubstantial.
The claims in this case are clearly not insubstantial.
See that this workaround has a not insubstantial price.
Not insubstantial for your average health care seeker.
Uses insubstantial information that is primarily common knowledge.
The absence of a writing is not insubstantial.
Too narrow and the porch will look insubstantial.
Weapons made from astral driftmetal can harm insubstantial beings as if they had the Affects Insubstantial modifier.