A more environmentally friendly option to disposable bags! One of the materials used to make this bag is cotton and it has a volume of 20 litres.
From Amazon
Fjallraven 27240-050 Vardag Totepack Sports backpack Unisex Basalt Size One Size
The product is available from £65.91 at international stores.
Trekkinn
Fjällräven Vardag Totepack Backpack Grey