Long before the days of internet surfing, 24 hour cable television news, and Instagram, times were a quite a bit simpler, and to a great degree more social. The introduction of Kodachrome transparency film in the late 1930's was slow to take hold, thanks in large part to its initial expense and the interruption of a vast global conflict known as World War II, but by the mid-1950's, a social phenomenon was taking hold, known as the "Slide Show."
Family vacations in a more upwardly and outwardly mobile America were often documented increasingly in color on 35mm transparency films that were mounted in 2"x2" slide mounts and projected to family and friends on a pull down screen in the living room. Kodachrome was the most common medium for these presentations at first, but as the fifties progressed, films using other reversal processes became increasingly common. These included Ektachrome and Anscochrome, as well as others.
Around the apex of this phenomenon in the late 1950's, someone, somewhere, whose identity I am unable to determine, stumbled upon a rather interesting discovery that a 127 film frame of 4"x 4" could be efficiently mounted into a modified 2"x2" slide mount, put into the same slide projector used for 35mm slides, and projected onto a wall to create an even bigger square image compared to the rectangles of 135. Okay, well, actually it might not be quite the "Eureka Moment" I've described here, but as I am unable to ferret out the specific origin of this, it will have to do for now.
The result, in an era when the most common superlative adjective in the parlance of the day was none other than "Super," would thus be come to be known as "Super Slides." And it would result in a brief flurry of revitalization for what had been an increasingly marginal format in 127.
New 127 format cameras were developed in the late 1950's, specifically tailored to this market, ranging from the Baby Rolleiflex on the high end to the Yashica 44 and Sawyers Mark IV in the mid-market, to the Bell and Howell Electric Eye 127 on the low end. The craze for Super Slides lasted only a brief time, though 127 slide film would be still be produced for at least another 20 years, and mass-produced "Super Slides" would be regularly seen for sale at souvenir stands of tourist attractions for quite some time afterwards. Unfortunately, Kodachrome never made the leap to the world of 127, which likely had some negative consequences for the durability of the phenomenon, not to mention the slides taken in the early days of this era.
Today in 2016, the "Slide Show" as we think of it is almost entirely a thing of the past, while "Super Slides" are an almost forgotten footnote of that past. However, the machines designed and manufactured specifically to target to this "fad" remain and are often in fully working condition. Yet, for the few who both collect and use these photographic gems, their use is often limited to black and white or color negative films rather than to the medium for which they were marketed. But, to the resourceful and oddball few like myself, a true "Super Slide" taken in the present is still entirely possible, given a bit of effort.
A look at some super slides of 40x40 mm image size compared to 36x24mm slides taken on 35mm film stock.