Roka Bags of London make the Finchley A Large Backpack from 12-13 recycled bottles collected from beaches to help reduce plastic in the ocean. As well as using recycled plastic these bags require less energy in production - so reduce carbon emissions too!
This model is in Ocean Blue, so will go with many outfits.
Made to last, and to be comfortable you will find the bags have pockets to keep organised - bottle pockets on the sides, padded laptop slot, phone and even pen holders.
The back is padded to ensure comfortable carrying with wide web straps, and there are grab handles at the top.
Rucksack approx: 45 x 32 x 14.5 cm.
For a smaller, more compact version of this bag check out the Finchley A Medium Backpacks.