Back to school shopping is in full swing, in fact some schools are opening their doors any day now, while others still have a few more weeks of summer vacation before the first bell rings. That said, many of us moms are already hitting the stores, tackling long lists of classroom supplies. One thing that all of our lists have in common, no matter the grade of our school-aged kids, is backpacks. Children both big and small can’t leave home without one, and so we’ve done our homework and rounded up the best satchels for lugging everything from a sack lunch to heavy text books.