Sunbrella Shade Sails also available in several shapes like squares, rectangles, triangles or custom sized polygons. They can be purchased in your choice of eight great colors and according to the size you want. Typical shade sail instructions for installation can be found below to read and follow the instructions. Sunbrella Shade Sails have to be installed with at least an 20 degree slope to allow water to run off the sail and not pool or stored on top of the sail. So one should fix it properly.Due to the limited available Sunbrella fabric widths, there will be seams approximately every 40-57 inches.