"全棉单面布" can be translated as "100% cotton single-jersey fabric" or more simply "all-cotton single-jersey knit".
全棉 (Quánmián) → "100% cotton" or "all-cotton" (emphasizing pure cotton composition).
单面布 (Dānmiàn Bù) → "single-jersey" (a common knit structure with one smooth side and a looped reverse) or "single-knit fabric".
"Single-jersey" is the standard term in the textile industry for this type of knit.
If emphasizing fabric use (e.g., T-shirts), you might say "100% cotton single-jersey T-shirt fabric".
Let me know if you need further clarification! 😊