蠶 Silk silkworms thickest wild Tussar oak muga

 https://www.wikiwand.com/en/Silk

https://zh.wikipedia.org/zh-tw/%E8%9A%95 

https://www.fibre2fashion.com/industry-article/5734/effect-of-selected-pretreatments-on-properties-of-oak-tasar-silk-fabric