Thinness.
Thinly.
Having opposite surfaces very close to each other; not thick.
Sparse; rare.
Having little substance or consistency.
I like you the better for holding to her through thick and thin. – The Complete Project Gutenberg Works of George Meredith by George Meredith
Thin, if you will excuse me, I'll go about me work. – The Hollow of Her Hand by George Barr McCutcheon