History of blouse
Blouses usually have buttons reversed from that of men's shirts. The buttons are normally on the wearer's left-hand and the buttonholes are on the right. The reasons for this are unclear, and while several theories exist none have conclusive evidence. Some suggest this custom was introduced by launderers so they could distinguish between women's and men's shirts. One theory purports that the tradition arose in the Middle Ages when one manner of manifesting wealth was by the number of buttons one wore. Another that the original design was based on armour which was designed so that a right-handed opponent would not catch their weapon in the seam and tear through, and also that a person could draw a weapon with their right-hand without catching it in a loose seam of their own clothes. Female servants were in charge of buttoning their mistress's gowns (since the buttons were usually in the back). They tired of attempting to deal with buttons that were, from their point of view, backwards and as such they started reversing the placement when making or repairing them. Another possible reason is so men can easily undo blouses as, from the front, buttons are on the same side as a man's shirt. One other theory is that women were normally dressed by their maids, while men dressed themselves. As such, women's blouses were designed so it could be easily buttoned by the maid but that of men were designed so it could be easily buttoned by the person wearing it.
While most women prefer to have the top button open for better comfort, some blouses made for women have looser necklines so the top button can be fastened without compromising comfort, but giving the same stylish appearance.Some women attach various pins and ornaments to their blouses over a fastened top button for style. Some of these attach directly to the button itself, others to the collars.
Some Muslim sects require women to wear blouses with the top buttons fastened while in public for modesty. Members of these religions who find this uncomfortable will often circumvent this requirement by wearing a crew-neck or mock turtleneck shirt under their blouse. Some blouses do not have a top button at all, and collars are styled to be open. They also form part of some nation's traditional folk costume.