Most of the early Bubblebacks displayed time only. The original model featured subsidiary seconds, which later changed to sweeping seconds. Later models also included the date, becoming the first DateJust models produced by Rolex. In 1935, Rolex developed the “Super Balance,” a streamlined balance wheel that improved the functioning of the Auto-Rotor. Rolex then began producing the watch in three different sizes to make it more appealing to individuals of both genders. In 1941, Rolex launched a Bubbleback model intended specifically for ladies.
Most popular versions of the Bubbleback are Steelium (stainless steel), Rolesor (half gold, half steel) and gold (9k, 14k, 18k pink or yellow gold). The terms Steelium and Rolesor are unique creations of Rolex, who patented them in 1931 and 1933 respectively. Case style variations include engine-turned and smooth bezels as well as some with the hooded lugs. I was told that the hooded model was rare and was made for the US market,
More variation can be seen in the dial designs, which differ between black, pink or white dials, two-tone dials, 24-hour military-style dials and an atypical California dial with mixed Roman & Arabic numerals.
Even though the popular watches now is the sports model, The Rolex Bubbleback is a very iconic watch and a coveted collector’s piece and has always been very close to my heart.
This afternoon, in my effort to streamline and reduce the quantities of my watch collection, I have managed to swap my Herdomas 8 days watch + Rolex 6694 and top up for a Rolex hooded bubbleback ref 6064, with the dial that I don't have.