Pirastro Cello 901100 resin is bright cherry red. It is used for cello and is softer than the resin used in violin bows. In choosing the appropriate resin you must take into account the material of which the string cores you are using.
Thomastik Spirocore strings have a flexible multi-strand spiral cord core. They provide a longer period of musical vibration and significantly reduce inertia. Spirocore strings are equally effective when playing with bow or pizzicato. They respond very well and are long lasting.