In order to eliminate the luster of the fibers, slices containing anatase titanium dioxide (TiO2) are used to reduce the luster of the fibers. If there is no T iO2 in the section, it is a bright filament (or a large filament), a semi-dull filament containing 0.3% titanium dioxide, and a fully dull filament containing 1%.
If you want to get a colored FDY, you can add a masterbatch at the spinning time or put the finished silk into a dye bucket for dyeing.