Anything natural nature can quickly break it down so, it doesn't pollute the earth, unlike man-made petrochemical materials such as nylon and polyester, which most backpack fabric is made from.
In an effort to thwart polluting landfills while keeping up with consumer demand, some companies are resulting to melting and spinning PET polyester (i.e. plastic bottles) to make textile polyester yarn for a host of gear, including backpacks such as the Osprey Arcane Day.
While not as ideal as using a bio-gradable sustainable material such as cotton, recycled polyester eliminates the new creation of virgin polyester, making the Osprey Arcane Day a more eco-friendly alternative.
Everything about the Osprey Arcane Large Day pack is recycled or re-used from existing materials, according to the global recycled standard (GRS). This includes the 500D (500 denier) recycled polyester outer-shell. Five hundred denier polyester is heavy duty (tear-proof) fabric used in pop-up tents and canopies, making the Osprey Arcane Day a very durable everyday bag.
The Osprey Arcane Large Day has a 20 liter capacity with an army green fabric lining the interior of the bag. There are four open pocket sleeves and one large zip pocket sleeve, which measures 18cm high and 27cm wide. The zip pocket has a standard col zipper and integrates a non-stretchy fine mesh section that makes the zip pocket breathable.
The largest of the internal open pocket sleeves are designed for a laptop (up to 15 inches) and a large tablet, although you can store something else like a graphic tablet, notebook or A4 binder.The laptop pocket sleeve measures 13 inches and 11 inches wide, while the tablet pocket measures 11 inches tall and 10.5 inches wide.
The front of the laptop pocket divider is padded (approx. 1cm thick); hence the laptop has front and back protection against bumps. That said, there is no padding along the sides of the laptop or tablet compartment.
The other two internal open pockets are smaller in size and can fit a pen and smartphone. These pockets measure 12.5cm high and 3cm wide, and 12.5cm high and 8.9cm wide respectively. The red cord next to these pockets is, in fact, a plastic key clip attached to a 2.5 inch long nylon webbing.
The height and width of the Osprey Arcane Large Day pack is 18 inches tall and 12 inches wide. The Arcane Large Day can expand approximately 12cm outward. It can, probably, expand a couple more centimetres, although that would depend on how much you would want the bag to bulge out.
Access to the main compartment is gained by unzipping the YKK 10RC (racquet coil) zipper heavy duty sliders, which integrate hard plastic pull-tabs attached to a short nylon cord.
These pull tabs have the same quirky pencil-eraser design seen on the Arcane Duffel backpack which is visually similar to the Arcane Large Day pack but bigger and more functional since the Duffel backpack can be converted into a nifty briefcase.
The Arcane Large Day reverse coil zipper has plastic teeth, which don't show from the front, which provides better water protection than basic coil zippers, although none of the zippers on the Osprey Arcane Large Day are waterproof because the zipper seam aren't PVC coated.
Speaking of zippers, the zipper on the Osprey Arcane Large Day pack runs from the bottom of one end and terminates three-quarters high at other end, which basically means the main compartment Arcane Large Day opens mainly side ways at an angle.
Many bags/backpacks, such as the Arcane Duffel mentioned earlier, have a clam-shell style opening, which is very useful on a large backpack.
Being that Arcane Large Day is much smaller with only a 20-liter capacity, the angle style opening isn't a hindrance since you can easily gain access to the bottom of the bag. If you do require a slightly larger bag, you should definitely go for the Archeon 25. It is a 25 liter backpack that can expand up to 30 liters and, it integrates a nifty torso suspension system.
Externally, the Arcane Large Day has a total of three pockets, one of which is a large zip pocket compartment located on the front of the bag. This compartment is lined with dark blue neo spacer mesh material. The compartment measures 24cm tall and 25cm wide and doesn't run all the way down to the bottom of the bag.
The other two compartments are small elastic pockets. One is located on the side of the bag and features a small pull tab; while the other is a breathable mesh pocket sewn onto the front of the left backpack strap. Both of these elastic pockets are large enough for a smartphone.
The grab handle on top is padded with thickly woven webbing that measures 2cm wide and 1cm wide, which is wide enough to fit a hand with a 8.5cm wingspan.
The  Arcane Large Day has two comfortable back straps, which have an ergonomic S curvature and terminate into loopholes.
The straps measure 18 inches long, 2.5 inches wide and half-an-inch thick. The padding is firm but springy, which helps with heavy loads. There is neo spacer mesh on the backside of the straps and a long ridge that helps with air flow.
Metal hardware (also recycled) is found in the zip sliders, back straps webbing buckles and flat carabiner G style clip, which  lets you detach the right back strap from the bag. The left back strap is sewn to the bag.
The purpose of the carabiner G style clip is to allow the right back strap to act as a bike chain, letting you quickly undo the strap to loop it securely around a table or chair to prevent anyone pinching the bag and running off with it.
The entire backside of the Arcane Large Day is padded with the same comfortable ridge foam padding found on the Arcane Duffel, which does a good job of ventilating the backside.
The ridge padding spans the entire length of the backside of the bag (18 inches by 11 inches) from top to bottom and side to side. The light blue color section on the backside measures 15 inches high and it's made of a thinner denier breathable material.
There is no reinforcement at the base of the Arcane Large Day like you get with the Farpoint Wheels 65; hence the base is made of the same 500 denier polyester as the rest of the bag, which has a PFC free DWR (durable water repellent) chemical-free coating applied to it from factory that makes the Arcane Large Day water-resistant (hydrophobic).
The Arcane Large Day bag is not waterproof though since DWR is just a surface treatment and there is no waterproof membrane material to prevent water saturating the bag; hence you want to keep this bag out of any rain downpours.
While the Osprey Arcane Large Day doesn't have the usual side pockets for storing water bottles, it works well as a small backpack that you can take with you on vacation. The Arcane Large Day only weighs 600 grams and stores flat very thinly when empty so, you can easily store it inside a suitcase. You can buy the Osprey Arcane Large Day from Amazon. Check out the review of the Transporter Rolltop.and Arcane XL Day backpack and Osprey Talon Earth 22 Limited Edition techncal daypack