This disclosure relates to a venting retainer for a tire curing tube, bladder or the like including means for generally porously encapsulating a tire curing bladder exteriorly thereof whereby upon the upon the insertion of the encapsulating means and the tire curing bladder into a tire internal air is automatically vented to atmosphere. The encapsulating means is preferably composed of a plurality of criss-crossed strands, said strands are secured between a pair of plates, and said plates are relatively movable toward and away from each other to vary the configuration of the encapsulating means prior to and during the insertion of the encapsulating means into a tire adapted to be cured in an associated matrix.