In 1993, the first sanitary napkin looked like a bullet. Since the invented of sanitary napkin, the shape of it has developed into many types in order to meet the needs of user.
One kind of sanitary napkin is the basic shaper (rectangle with both ends are round) with flank, which also named butterfly wing. The shaper of flank is different from manufactures, some are arch, and some are square. Sanitary napkin's flank is design to avoid leak with caused by exercise. And the design is divide into direct absorb and leakproof broadside, the material of these two design are also different. The material of direct absorb flank is similar to sanitary napkin itself, while the flank of leakproof is made of non-woven fabric which has special sewing design.
According to different volume of menstrual blood, sanitary napkin has developed to long-size, night size and so on. The length of basic sanitary napkin is about 20-23 cm, while the long-size and night-size are about 28-30cm, what's more, the end of night-size are broader so it can avoid the leak in night. There is also exist slim sanitary napkin. Pad is a special one. Pad is designed to absorb the private's secretion before menses. The pad is about 15cm long.
With the different kinds of sanitary napkin, women can choose the suitable one according to the time, volume and other factors of menses.