I just finished a book that involves using needle lace designs as encrypted messages! The Curse of the Flores Women is by a Brazilian author (Angelica Lopes) and is set in the Brazilian state of Pernambuco. It follows 7 generations of a family and is a dual timeline story, set in 1918 and 2010. The 1918 women use their lace skills and income to seek freedom in a male-dominated culture.