to hold the cover in place.
your shade sail(s) may be cleaned at any time using a solution of mild detergent and water. apply the solution with a sponge or a very soft brush. let the solution stand on the fabric for 10 minutes and rinse thoroughly with water from your garden hose. 3 sides of each box.
cut 3 sections of baker's twine into 20" lengths. tie 1 onto each side of the box. glue the not hole punched side of the box to the canvas, about 2" below each balloon.
bring the twine ends over the balloon to the top. glue and trim excess. 