i‘m making a backpack for high school so i need a strong material people have recommended duck cloth and polyester i‘ve read that duck cloth shrinks so i don‘t know and polyester how strong is it because i weighed two of my textbooks and together they weighed about 10 lbs. also can you recommend a sewing machine that can sew strong fabric i‘m fourteen so something easy to use as i don‘t know much about sewing it doesn‘t need to have a lot of stitching patterns and it needs to be under $200
