Dutch designer Floor Wesseling dived deep into the phenomenon of heraldry, the visual coding system from the 15th century by which families, kingdoms and armies could be identified and which were placed on flags, shields, jerseys and coats of arms.

The designers of heraldry were the first graphic designers. Today we can find a lot of similarities, especially in the urban environment and on the jerseys of football clubs and the shirts of national football teams.
Blood In Blood Out wants to show the relationship between cultures and express this by displaying new jerseys for football players, who are very much the modern day heralds. Floor Wesseling combines jerseys from different football teams into new combined jerseys and in doing so tells emotional stories about rivalry, social communities, city and country derbies and latter-day football battles.

The book also contains a short introduction to the system and symbols of heraldry.