Bin liners 'eco friendly'

Bin liners. They can be very annoying, no? How many times have you bought the wrong size? Who in their right mind can picture the litre capacity of a bin bag? Not me. So these, to be clear, are for the size of bin that fits under your kitchen sink (and swings out as you open the cupboard door). Know what I mean? OK, so the actual measurements are 70x50cm.  30litre capacity. They are made from 80% recycled material.... so they're getting there.