Early Brownie "Film"

Back in the early days of the Brownie you returned the camera to Kodak for processing. The film was actually emulsion on paper, and during processing the emulsion was floated off the paper and put onto glass for contact printing. I've never seen a sample of that paper. How was it made so that the emulsion wasn't permanently stuck as modern papers seem to be?

In short, can I float my paper emulsion off to a glass plate?

Bruce

A special "stripping" paper was used, as you probably know. The subbing layer for the emulsion was probably a much softer bloom gelatin than the emulsion holding the silver and could be dissolved with mild heat and or additional chemicals.

I have often wondered how they managed to float off the emulsion and keep it from wrinkling on glass on an industrial scale.

Since the business model of Kodak was firmly grounded in patented processes, there might be a clue in searching the US Patent Office records for that time period. There might be a clue in some device used to strip the emulsion from the paper; the trick is to possibly find it!

I would think by the time a modern emulsion floated off a modern photographic paper, it would be essentially destroyed and unfit to print, but I could be wrong.

You're conflating the 1888 Kodak and the 1900 Kodak Brownie.

The 1888 Kodak was the one that utilized stripping film. The alternative was paper base film which was treated with castor oil to make it more translucent, but the stripping film was superior in image quality.

The stripping film consisted of the silver-gelatin emulsion applied over a water-soluble gelatin layer, in turn applied to a paper base strip offering 100 exposure frames. When the exposed film was returned to the Eastman factory for processing, the film was first steamed to dissolve the soluble layer, and the emulsion layer was then transferred to a clear gelatin or glass base for further development and processing.

By 1890, stripping film had been supplanted by transparent nitrocellulose film.

By the time the Brownie was in production, only transparent film was available.



@laser Robert Shanebrook's Making Kodak Film Second Edition has details on the paper, stripping and transparent film types.

Thanks, Hunter.

Not that up on very early Brownie facts; appreciated.

What I remember from a documentary I saw decades ago was a 100-photo paper strip being developed, I think cut into frames, then by hand underwater the emulsion placed on a glass plate for a contact print to be made, then washed and recycled. I thought the camera was a Brownie, because it was a simple box. I thought the 100-frame load was generous, but destroying the negative wasn't.

If @Mark Osterman shows up, I'm sure he could supply lots of details.