緯糸

1. Origins, structure, and basic meaning

• Structure: 緯糸 (よこいと) is the weft passing across warp threads in woven fabric. 緯糸を通す is weaving; 緯糸の色 is a pattern-forming property.
• Basic usage: A craftsperson passes weft through warp; changing the weft color makes a fabric pattern stand out.

2. Common pitfalls and similar expressions

• Thread passed through warp and thread color shaping a pattern
  • It pairs terminologically with 経糸. The first sentence focuses on thread path; the second on the visual result of its color.