Reline impressions should always be verified for a perfect fit! You can do this by removing, rinsing and then replacing the impression back into the patient’s mouth to check for adequate suction.
Also important to note on the subject, recommended materials include VPS-Light Body, Polyether (Impregum, Permadyne), Polysulfide (Rubber Base) or Visco-gel and should be 2mm thick. In addition, relieve denture base if necessary (where impression material has been displaced).
All these efforts combined will result in predictable, accurate results for relines every time!