In many cases, a ''case back'' is only present for aesthetic and decorative reasons and may in turn contain specific decorations or inscriptions, such as the model number, but it is fixed. In other cases it is used to cover the access to the filling system (it is common in [[button filler]]s) and can be detached, usually by unscrewing it to access the mechanism, but in this case it has to be more properly called ''[[blind cap]]''. Finally, the case back can be a direct part of the filling system itself (for filler such as the [[piston filler]] or the [[plunger filler]]) in which it generally plays the role of the part of the mechanical device (and then is better called ''[[knob]]'') on which to act to activate the filler. | In many cases, a ''case back'' is only present for aesthetic and decorative reasons and may in turn contain specific decorations or inscriptions, such as the model number, but it is fixed. In other cases it is used to cover the access to the filling system (it is common in [[button filler]]s) and can be detached, usually by unscrewing it to access the mechanism, but in this case it has to be more properly called ''[[blind cap]]''. Finally, the case back can be a direct part of the filling system itself (for filler such as the [[piston filler]] or the [[plunger filler]]) in which it generally plays the role of the part of the mechanical device (and then is better called ''[[knob]]'') on which to act to activate the filler. |