its possible, but I cant seen to think of a DIRECT use of against for comaprison. But it could be used indirectly as: "The dark dress, Against the pale white of her skin, seemed even darker." As for comparison words: "When compared to A, B is ___. In comparison to A, B is __. "California's warm climate starkly contrasts to Ireland's consistent rains" "His rude demeanor juxtaposed (or was a juxtaposition to) that of his kind friend"