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Place your pattern onto your chosen material and outline the edges of the panel. Before cutting any material, understand that the edges of each panel will need to be stuck together and then sewn. Once you have outlined your pattern onto your material, including battens and seams, you may now cut out your pattern. When creating a seam with shape, you want the shape to be about 35% from the luff. Move from panel to panel while leaving extra cloth at the external edges of the sail. It's best to trim and adjust the sail shape once all panels are sewn together. Stick and sew two panels at a time until the sail is all in one piece. You can now trim it to your design on the table and draw on the batten pockets. Using dacron tape or reinforced monofilm tape, reinforce the seams. You can also glue a layer of cloth on either side of the material for added strength. There will be a high degree of force applied to these areas so ensure that they can withstand that amount of tension. Depending on the type of sail, attach the luff once you have dealt with the batten pockets. Measure the width of existing sails and adjust your sail accordingly. Sleeves can either be a single piece or made from a number of pieces of material but ensure that the head is reinforced and capable to withstand the strain from the mast tip. Create your sleeve so it fits down to the foot batten. Create an adjustable head for your sleeve if this is your first attempt at a sail. Use pulleys from old sails or get them from a sail maker.
Start with a central panel. Cut out your pattern. Stitch the materials. Reinforce the material. Fortify the foot and the batten pockets. Create the sleeve for the mast.