Hand Spray is the most versatile and popular production technique and the one normally chosen by new start-ups. A special spray gun is used to simultaneously deposit chopped glass fibre and cementitious slurry onto a mould. This is then compacted by hand using a spring roller. A second layer is then sprayed and again compacted. Using the spray technique allows high glass percentages to be used and this gives the highest mechanical properties. In turn this allows for reduced skin thickness and lighter products.