The impact of his actions was inappreciable.

The difference in taste between the two brands of soda is inappreciably small.

She was inappreciative of all the hard work he put into planning the surprise party.

Her inappreciation for his hard work was disheartening.

The inappreciability of her efforts was disheartening.

Her inappreciativeness towards his efforts hurt him deeply.

She looked at him inappreciatively.