When sourcing corduroy dresses, the wale count (number of ridges per inch) is the most critical technical spec. For a classic look, a 11-wale to 14-wale fabric is standard, while 'pinwale' (21+ wales) offers a softer, more velvet-like drape. Ensure the fabric composition is either 100% cotton for breathability or a cotton-spandex blend (2-3% elastane) to provide necessary stretch for fitted designs. Additionally, verify the fabric weight (GSM); a range of 280-350 GSM is ideal for autumn/winter collections to ensure durability and warmth.