Trying to explain the recycled content in these new boards to a client last week, and I accidentally described the paper facing as 'biodegradable napkin material'... he asked if that meant it would dissolve in humidity. Had to backtrack through the whole lifecycle talk Karen mentioned, which went about as well as you'd expect. Now I just bring diagrams to avoid mixing up compostable with moisture-resistant.
What's rarely discussed is the end-of-life cycle for these materials. I've had clients ask if drywall can be fully recycled back into new board, and the answer isn't straightforward due to paper facing contamination... That complexity is driving interest in alternative binders and facers that are easier to separate and process. Some manufacturers are now testing cellulose-based facers that compost instead of landfilling, which could really shift the sustainability metrics.