Saint Bartholomew (Matthew 10:3, Mark 3:18, Luke 6:14, Acts 1:13) is the patron saint of tanners and is usually depicted with a large knife and holding his own skin.

"He was flayed alive—the skin of his body cut into strips, then pulled off, leaving his body open and bleeding for a long time, then beheaded, wrote Fr. Paolo O. Pirlo, SHML, in My First Book of Saints."

[...]The flaying of the apostle Bartholomew, who is tortured to death for converting the brother of the Armenian king to the Christian faith and his resurrection presents his old skin to God at the Last Judgement as proof of his martyrdom.[...] Source: Skin; on the cultural border between self and the world by Claudia Benthien, page 68

Bartholomew shows us that our skin can, even after death, offer proof of our (honourable) deeds.