Launched by a large advertising campaign, the [[Da-Ma]] model was a good selling success, but the filling system, as it was innovative, proved to be very fragile from a mechanical point of view. Many pens went back to the factory, where the filling system was changed to a [[button filler]], losing the transparency of the pen body. | Launched by a large advertising campaign, the [[Da-Ma]] model was a good selling success, but the filling system, as it was innovative, proved to be very fragile from a mechanical point of view. Many pens went back to the factory, where the filling system was changed to a [[button filler]], losing the transparency of the pen body. |