I save a plastic pin for the end of the tube I DON'T want to open, and find a rubber wedge (or rubber band on short tubes) for the other end. Otherwise it's too often that I'll not notice that one of the wedges is already gone, and pick up a tube by the wrong end... BillW -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body