Highlights What's new • Blinding in clinical trials has the potential to reduce bias • There is a live yet underreported debate about the value of measuring blinding success • Interpreting the success of blinding can be problematic and potentially misleading • However, failure to report the success of blinding, if it is measured, seems like wilful withholding of information that is at least potentially useful • We suggest a middle road whereby the success of blinding be measured (where...