2 Metaphors for blemish

The capital blemish of that work, is, the unharmonious versification, which gives perpetual offence to the ear, neither is the language universally pure.

The only blemish in the sublime perfection of the picture is the introduction of the two small figures on the left hand; who, by-the-bye, were Cardinals, inserted there by command.

2 Metaphors for  blemish