In its patent Apple, which uses a lot of white paper bags points out that paper bags made of recycled material tend to be flimsy due to the amount of bleach used.
To fix this problem Apple has come up with a solution by holding the bag together with such a high proportion of recycled material. Apple has apparently come up with a bundle of alterations that should help its bags remain white and environmentally friendly.
Those alterations include fancy reinforcements at the folds and gussets of the bag, another one at the bottom that sticks to the sides, and a handle “formed entirely of paper fibre yarn knitted in an 8-stitch circular knit pattern”.
Of course you can expect that one day Apple will make the “brave step” of removing the handles and moving to something more wireless.