Once the line approaches its correct length, the operator is made aware of this by a bell or other indicator. If the line is ‘loose’ or too short, there is too much ‘white space’ for the space band wedges to fill out the line, and the matrices could possibly turn sidewise or fail to seal against each other as the machine prepares for the casting operation. If the line is ‘tight’ or too long, the elevator carrying the matrices and space bands will not seat properly in front of the mold slot. Both the Linotype and Intertype machines have two important safeties that act during the casting operation—the ‘pump stop’, which comes into play on loose lines, and the ‘vise automatic', which comes into play on tight lines. Both scenarios, if not stopped by these safety features, usually result in a “squirt” of molten type metal, encasing the matrices and the elevator in metal in the process. Not only is it time-consuming to clean up after a squirt, a tight line usually has not come down far enough to mate with the slots on the mold face, resulting in damage to the matrices. Therefore, it is considered very poor form for an operator (or the machinist who cared for the machine) to permit this to happen.