Remember that any bag, backpack and especially, should be light, durable and intelligently allocate anatomical stress on the body. Decide on the type: soft (city), frame, easel backpacks are designed for different functions. City - to transfer small compact cargo frame - for hiking, heavy machine - for climbing or caving.
Note the fabric from which sewn backpack on accuracy seams, pockets and inserts. Take a look inside, backrest all quality products should be covered with breathable fabric for ventilation back. If you choose a large, serious backpack, check the chest buckle, it affects the distribution of weight on your shoulders and hips. Take the shoulder straps, pull them, check that they are regulated in length, have a cushioned surface to avoid crashing into the shoulders.
Try on a backpack, noting the following: the width of the product must match the width of your torso; the upper edge of the backpack can not be above the shoulders, lower - below the waist; backpack fits snugly to the back, as if repeating its shape. Put the goods in the selected product, wear and walk. Check the practicality and convenience of a backpack. Choose a neutral tone, as bright and flashy colors are not practical, and not accepted among the true lovers of backpacks.
Please note that the main indicators of quality are the things - weight (no more than one and a half pounds), fabric, orthopedic backrest (preferably a small roller for lumbar support), straps, fasteners, joints and fasteners. Professionals advise to buy the necessary and universal attribute in sports shops, where there is a really great choice.
Buy one, but a quality backpack, because it is this thing can be your good helper in all situations.