When sourcing high-quality selvedge denim, you must prioritize fabric weight (measured in oz/yd²), typically ranging from 12oz to 21oz for premium goods. Ensure the supplier uses shuttle looms to create the characteristic finished edge. Key indicators of quality include indigo dye depth (rope dyeing vs. slasher dyeing), shrinkage rates (Sanforized vs. Unsanforized), and the slub texture of the yarn. For B2B buyers, verifying the tensile strength and colorfastness to crocking is essential to meet international garment standards.