Cut four fabric border strips, each about 1" longer than the sides of the rug. To determine the width of the fabric strip, double the desired finished width of the border, and add a 1" seam allowance. We used 5"-wide strips for a finished 2"-wide border. Fold and press a 1/2" hem inward on both long edges of each fabric strip. Fold each strip in half lengthwise with the right sides out and press.
Attach the borders to the ends of the rug first. Tuck the edge of the rug into the border, and run a line of hot glue along the length of the fabric border, front and back, and hold in place. Cut the two attached borders even with the rug on both ends.
Hot-glue the back of the next border in place, and fold the end of the border to the front so it's even with the edge of the rug. Fold the corner fabric at an angle to create a mitered corner, and hot-glue in place. Miter the other three corners, and hot-glue all the edges to the fiber rug.
Decorate a plain natural-fiber rug inexpensively by adding a border with stencils and stencil paint, or spray-paint a rug, using masking tape and newspaper as a resist. Cover areas to remain unpainted with masking tape -- large areas with taped-on newspaper -- and spray-paint to create borders and stripes.
A highly patterned natural-fiber rug can be painted with indoor/outdoor paint. Just brush paint on patterned areas to make a design.
Protect painted-fiber rugs with a clear sealer, applied to both sides of the rug, to prevent the colors from bleeding through to the floor or carpet beneath. Natural fibers can be very slippery; place a piece of nonskid fabric under the rug.