When sourcing knitting yarn fabric, the price is primarily driven by material composition (natural vs. synthetic), yarn count (fineness), and fabric weight (GSM). Buyers should prioritize fabrics with high colorfastness (Grade 4 or above) and low shrinkage rates (typically <3-5%). For high-end apparel, ensure the yarn is combed rather than carded to reduce pilling and improve hand-feel. Always request a specification sheet that details the blend ratio, such as 95% Cotton 5% Spandex, as even a 1% difference in elastane can significantly impact both price and elasticity.