Although the skin, stem, and seeds are often used in making the
nutritional supplement, grape skin extract, the extract sometimes
contains grape skin only.
View page
Red grape skin extract capsules: 200 - 600 mg at 30 %
anthocyanins.
View page
It depends on the grape If the grape has a few flat sides then some of the skin will be flat. But because grapes aren't flat it would have to have to have a curve wouldn't it if you think about it