The transparent Swatch Jelly Fish was introduced in 1985. Its clear plastic case and strap exposed the colorful hands and quartz movement, turning the normally hidden mechanics of a watch into part of its visual appeal.
The model is commonly identified by reference GK100 and became one of the most recognizable early Swatch designs. Transparency was especially suited to Swatch’s plastic construction: instead of presenting plastic as a cheap substitute for metal, the design made the material itself the centerpiece.
Collectors can encounter confusing variations because Jelly Fish versions appeared across different years and markets, and older clear plastic can yellow or become cloudy with ultraviolet exposure. The year printed on some dials can also refer to the design or original model rather than the exact production date of a particular example. Those later variants do not change the standard answer for the original Jelly Fish introduction: 1985.