It may seem like a silly question, but it's more complicated than you think.
Because Envirobank's orange collection bags are reusable, we kindly ask that you pull the drawstring tight but don't tie the drawstring in a knot to keep the bag closed. Tight knots mean our processing teams often have to cut the drawstrings to open the bags, which means they cannot be reused until the drawstring is replaced.
Instead, we suggest taking the ring-pull off an aluminium can (there's a good change you have one inside your orange bag). Thread the drawstring through the hole on the ring-pull and slide it down towards the bag. The ring-pull works like a toggle, and keeps the bag securely closed, but is easy enough to remove when we need to get to the containers inside!
Another option is to pull the drawstring tight, then loop it around the top a few times and tuck the end under one of the loops.