Sew a "tunnel" on the upper border of the fabric: fold and roughly stitch 2 x 2 cm. Fold the fabric longwise, creating a narrow strip. Prepare the dye bath according to the manufacturer's instructions and shortly dip the wet fabric to 5 cm before the desired color height into the color - then immediately pull it out a bit. The color will bleed up higher into the fabric. Allow the color to soak in and then again pull out a bit of fabric. Repeat the procedure several times until the desired color gradient is achieved. Wash the fabric thoroughly, let dry and iron. Remove hanging threads around the open borders.