When sourcing designer-grade jackets, the fabric composition is the primary indicator of quality. For luxury segments, prioritize natural fibers like wool, silk, or high-grade leather, or technical fabrics with Gore-Tex or Cordura certifications for functional fashion. Pay close attention to stitching density (at least 10-12 stitches per inch), the alignment of patterns (especially for plaids or logos), and the quality of hardware such as YKK or Lampo zippers. Ensure that the lining is made of breathable materials like Bemberg or Viscose rather than cheap polyester to maintain the premium feel.