Physical description
Reckitt's Bag Blue - Four knob pack - Cardboard container with four knobs, each in a paper wrapped bag, and made of powdered ultramarine and baking soda
Inscriptions & markings
Reckitt's Bag Blue / Four knob pack / Out of the blue comes the whitest wash / Prevents yellowing Keeps your clothes dazzling white
Squeeze the bag in the last rinse & stir. This keeps your linen white. Robin starch for better starching.