What type of fabric is described as a firm knit with reduced stretch that is produced using two sets of needles?

The type of fabric described as a firm knit with reduced stretch, produced using two sets of needles, is indeed double-knit. This fabric construction involves two layers of material being knit simultaneously, which results in a thicker, more stable textile compared to single-layer knits. The use of two sets of needles creates a fabric that is less prone to stretching and provides greater durability, making it ideal for applications such as activewear or structured garments.

In contrast, single knit fabrics are made with one set of needles and typically have more stretch and less firmness. Jersey knit, commonly associated with its smooth surface and stretchable qualities, is also produced with a single set of needles, making it a different construction from double-knit. Rib knit features a pattern of raised and lowered stitches which gives it elastic properties; however, it is generally constructed in a way that prioritizes stretch rather than firmness. Thus, double-knit is the correct choice for a firm knit with reduced stretch produced by this specific knitting technique.