When sourcing cotton lace, the primary focus should be on the purity of the cotton fiber. High-quality lace should be made of 100% combed cotton to ensure a soft hand-feel and durability. You must check the yarn count (e.g., 30s, 40s, 60s); a higher yarn count typically indicates a finer, more intricate lace pattern. Additionally, verify the tensile strength to ensure the lace does not tear easily during the garment manufacturing process. For high-end fashion, prioritize mercerized cotton lace, which offers a subtle luster and better dye affinity.