6d mainly uses multi-layered eyelashes and multiple flowering techniques to make eyelashes grow thicker, so as to achieve the effect of not changing eyeliners into electric eyes, light and no sense of weight, and 9d is based on 3d and 6d is technology, which is an upgrade of 3d plus 6d Version, it can make eyelashes become layered, this technique of grafting eyelashes is more difficult. I hope you can choose the grafting method that suits you and become more and more beautiful.