Covering Skin With Grease or Tar
Before the enslaved men and women were placed on the auction block, they often would be washed and their skin covered with grease, or sometimes tar, to make them look healthier, according to an account on historyonthenet.com. This was done so they would fetch as much money as possible. Sometimes they would have grease slathered on their lips so that it appeared as if they had just finished eating meat — though it was unlikely that they were fed meat.
The Power of Advertising
Slave traders who lived in the city were listed in public directories, while the enslaved were often advertised on posters, fliers and publications the same way we might see advertisements for homes and cars today, according to historian Frederic Bancroft.

