Border prints are a special fabric with a design. This design is usually along one lengthwise edge (parallel to the selvage). Some border prints will have this design along both lengthwise edges of the fabric. Many come with a coordinating print.
Horizontal borders are ideal for hemlines, bottom of sleeves, collars, yokes, and neckbands. Think about the kind of illusion created by the placement of the border.
Vertical borders tend to add height. They are used for the "centers" of sleeve, bodice or skirt. You may also see these used off center on a bodice and skirt.
Border prints are unique and should be a nice addition to the wardrobe. This is an opportunity to bring out the designer in each of us. Have fun being creative and expressing your individuality.