I remember during my achool.days we had to cover our books and it did not really matter which material we used. I initially started with newspapers. Later shifted to clear transparent plastic material then finally to thicker coloured plastic covers which I obtained from an oil factory free of charge. These helped to protect my books during rains as I did not own an umbrella back then. These days however, schools sell a uniforms of book covers for the whole school. Parents are forced to buy this. Which do you think is more economical?