It is a semisheer lightweight material, which could be silk, cotton, or linen.
(It; is; a semisheer lightweight material, which could be silk, cotton, or linen) (a semisheer lightweight material; could be; silk, cotton, or linen)
It a semisheer lightweight material
is could be
a semisheer lightweight material, which could be silk, cotton, or linen
silk, cotton, or linen