Breast pads are clothing items which are inserted or sewn into the chest part of many garments which create the appearance of breasts in both sexes. They first appeared in the Mars Suit of the Space Race Trend because Mars suits needed to fit the wearer precisely and with the addition of breast pads it became possible to cut larger numbers of garments in the same way, enabling more economies of scale. They were later adopted into other clothing for the same reason, but are also linked to the unisex trend, in that they are used by both men and women. They parallel the earlier trend for shoulder pads in that they create the appearance of an exaggerated secondary sexual characteristic in all genders. Some breast pads are made of foam, others are either inflatable or use a kind of gel in order to enable them to be adjusted according to the wearer's anatomy. The advent of rigid zips also meant that there would be a disconcerting "void" in front of the chest for some people, which they were able to fill in.
They are also used to protect nipples during breastfeeding.