I would like to ask what this representation method for polyester yarns means
Thread Content
21S/5, 20S/3 polyester threads: We use these for sewing bags. I’m not sure whether this refers to one single model, namely 21S/5, 20S/3, or whether it are two separate models (21S/5 and 20S/3)
21S/5: 21 indicates 21 strands of cotton; it represents the length that can be drawn out per unit weight. The higher this number, the finer the thread. The number after the slash denotes the number of threads per strand. In general, it’s 21 strands of cotton, with five threads per strand.