Thieves Guild Style
The Thieves Guild Motif Chapters (or entire Motif) are obtained through the Unidentified Equipment Boxes which are rewards for performing Heists to the Thieves Guild’s highest standards. You will need the Thieves Guild DLC to obtain this Motif.
Thieves Guild Style Materials
The style material used to make items in the Thieves Guild style is called Fine Chalk. This material is made up from 10 pieces of Coarse Chalk.