A backpack is not just the face fabric
Now commonly used material for the nylon bag and Cordura two. Although the more wear-resistant canvas, but easy to damp, wet, not dry and heavy mass, so rarely used. Nylon quality of light, not moisture, mildew, dry fast, strength is not bad; disadvantage is not afraid to wear and fire. Cordura nylon fabric is a synthetic, reusable bag but it's performance on the wear and strength better than nylon, the same will not absorb moisture, mold, and quick-drying and sticking snow, but slightly heavier than nylon.
Second, the capacity is not just how much the band
Knapsack capacity is an important factor in purchasing: size is not enough capacity, the goods to hang out cumbersome and easily lost; while the capacity is too large when the backpack is not easy to pack a solid, action package for mobile equipment will affect the balance. Therefore, nonwoven bag  the choice must first create a personal capacity backpack equipment list.
Third, bone backpack carrying system
Backpack suspension system can not completely solve the problem of the weight of the backpack, recycle PET reusable bag its main function is to a reasonable weight assigned to all parts of the body, to avoid the weight concentrated in the shoulder. In addition it provides the focus adjusted to bear in order to increase the balance of action and safety. Medium and large frame back pack usually constitute a suspension system for the center, back frame can be divided into outer and inner shelf frame two.
External frame backpack backpack external frame backpack is fixed in a rigid framework (the most common aluminum alloy), the taut nylon shoulder strap and hip strap. This high center of gravity backpack, shoulder or shoulder more about. Although the design of the high center of gravity of the occasion requires a high degree of balance is not suitable for, but bear in a flat on the road will feel more comfortable. This bag is also filled with easy-access items, and can make the weight from the shoulders and hips shared. As the external frame backpack is saddled with a shelf, so good back ventilation.
In some cases, the framework will become very convenient: for example, drilling lines in dense forest, rpet bag bamboo, the backpack easily be hooked stuck; climbing or skiing in the center of gravity shift suddenly easy to lose balance. In short, external-frame backpack to go flat more suitable for long-distance journey time.
   Within the frame backpack
Lower center of gravity within the frame backpack, about the shoulder and hip can be adjusted in between. Need to maintain balance for climbing situations, backpack shoulder height to prevent shaking.
Fourth, the backpack to buy - vary according to local conditions
Shoulder belt adjustment range must match the length of the back, in order to make the focus falls on the desired location; hip belt must be able to tie on the hip bone. Backpack should also be seen from the back of the buttocks and legs, she is more petite women should pay special attention to this point, not on his backpack and can only see from the backpack and the calf after it is very wrong and dangerous.
Buy backpack, you should first release together with all the weight adjustment, because you can not know without the weight back up feeling backpack, non woven bag china carrying the adjustment range is appropriate, back pack containing aluminum should be checked after the arc and back curve is consistent, if not, check whether aluminum bent; if they can bend the aluminum used for a period of time will naturally coincide with the back bent curve. Backpack shoulder strap and shoulder joints to be lower than 5-8 cm, and the shoulder strap and backpack gap between the smaller. Shoulder strap can be adjusted with the width of the opening and closing the chest, shoulder belt can make a more comfortable position on the shoulder, backpack and can prevent shaking. With good use of these adjustments and filling techniques, you can adjust the weight between the shoulders and hips, so that different parts can share the weight of muscle.
When the bag to adjust to the most appropriate location, you should check how the head of the line of sight? Can look up and not hit the top of backpack? Wear a helmet is still looking to the sky? Contact with part of the backpack recycle PET bag is comfortable and breathable back? Particular attention should also shoulder strap, hip belt cushion width and quality.
In addition, there are some details that need attention:
Are there double bottom fabric design, this feature can greatly extend the backpack of life.
Is there towing ring, hanging ice ax loop. Multi-day trek and walking, if flexible capacity backpack design.
Are there side with the design of compression, when the equipment when it can tighten reducing backpack backpack to reduce capacity in order to prevent action in a backpack equipped with shift shaking impact road balance.
Is there easy to carry crampons, skis, snow shoes, trekking poles design.
Have removable side pockets, this backpack features allow flexibility to increase capacity.
Is there chest with a backpack design, in difficult and harsh terrain it can move to prevent the backpack.
If the backpack is used for climbing or jungle, the smooth shape of the backpack should be chosen to avoid being wrapped around a branch or rock trip.
      Backpack cloth material should be tough, more able to meet the needs of outdoor activities.
Backpack's zipper is directly affected by force? If it will be directly affected by the force of the force that limits how? If the zipper bag failure is also used.
Fifth, backpack filled - a great stress
Backpack filled with negative affect ease of use and comfort, or cause damage to the center of gravity offset and backpacks. Therefore, in addition to the first backpack filled with all kinds of items classified according to use, but also pay attention to two points: first, balanced center of gravity so strong; the second is for easy access.
The following is filling principles:
1, the quality of the heavier items on the upper back and as close as possible, recycle bag make the center of gravity close to the back to avoid the feeling of being pulled back. Bulky, lightweight items can be placed on the bottom, this does not affect the center of gravity; In addition, as a heavy object on top, so when using a backpack would be more dense after.
2, items not on the posted back hard parts, such as internal frame backpack or when the top is directly to the back and very uncomfortable, even when it hurt to fall back; such as external frame backpack due to hard goods and backrest are only separated by a layer of cloth bag, then it is easy to pack cloth worn.
3, about backpack weight should be placed on similar items, so as not to focus on one side. Raincoat, drinking water and what should be on the same day with the top or the most easily accessible place.
4 items are classified using the concept of bags: the simultaneous use of similar items or materials in the same bag for easy access, even the small things scattered so.
5, to develop the habit of placing point: not only fast finishing pack, and even the dark can also work out what they want in the backpack.
6, try to change the loading mode to minimize unnecessary backpack hanging outside, because this action will not only affect safety and is not beautiful.
Six pack on the shoulder, lower shoulder - pay attention to the potential recruit
Under the shoulder bag on the shoulder with a large backpack to use the basic moves. Shoulder on the more commonly used methods are: Station lunge feet, hands raised to live with a shoulder bag that will be on the front foot of the thigh, a hand first penetrated the shoulder belt shoulder to shoulder shore backpack, then the other hand also support rapid penetration of the other side of the bag on the shoulder strap to complete the action.
Another popular way on the shoulder: the backpack onto the high places, who can be a little squat with both hands shoulder penetration, stand up on the shoulder after the completion of the action. After completion of action on the shoulder Do not worry forward to deal with bags of various adjustments make appropriate adjustments to the most comfortable carry position forward. Backpack is the reverse action is under the shoulder, put down the bag should be gently down, Chongshuai very easy to damage the backpack off.
The second way is not only saving on the shoulder, but can not put down the backpack as a short break, we will from time to time in the halfway break large backpack leaning against the side of the road is high. To facilitate the backpack up and down or not down.