Making a transducer having a plastic matching layer which includes providing a transducer housing having a proximal end and a distal end, and bonding a plastic to the distal end of the transducer housing (the plastic fluidly sealing and occluding the distal end). The bonding further includes inserting a cylinder comprising a mold-release chemical into the transducer housing, bonding plastic onto the distal end of the transducer housing, and removing the cylinder when the plastic has hardened.