Which preposition to use with absorbent

of Occurrences 4%

Cotton and linen are good conductors of heat, but are not absorbents of moisture, and should not be worn next the skin.

by Occurrences 1%

Only this, probably: that the woman, whoever she was, had not the usual fancy of her sex for dramatizing her soul in her writing, her dress, her face,kept it locked up instead, intact; that her words and looks, like her writing, were most likely simple, mere absorbents by which she drew what she needed of the outer world to her, not flaunting helps to fling herself, or the tragedy or comedy that lay within, before careless passers-by.

Which preposition to use with  absorbent