The Essentiel Antwerp Hapricorn buttondown shirt updates a classic silhouette with square-sequin floral embellishments. The Essentiel Antwerp Hapricorn buttondown shirt updates a classic silhouette with square-sequin floral embellishments. Essentiel Antwerp is an ode to play. Going off-piste since 1999, the powerhouse was founded by duo Esfan Eghtessadi and Inge Onsea as a bold antidote to the minimalist, monochromatic fashion scene. Brand signatures like print, color, and proportion are found across an extensive ready-to-wear and accessories collection.