Tinkb wrote:
I am working with a historical society to convert some 3000 speed graphic negatives into digital format for records and preservation. The negatives were “stored” in metal boxes, in paper envelopes, in an unheated second floor of a local library. Using care in handling most of the negatives are producing very good images so here is my question, cost is a factor as this is a non-profit, but what would be the best way to preserve these negatives going forward? Paper sleeves, in plastic bags, just paper, vacuum sealed plastic, paper envelopes in a Tupperware type container? The newest set is 56 years with the oldest appx 75 years old.
I am working with a historical society to convert ... (
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SalvageDiver, in his reply to you, listed 3 reference links for you to further your research on preserving 50 to 75-year-old photographic negatives. If you dive further into the third link of RIT (Rochester Institute of Technology) publications, you'll find the most pertinent publication: Photographic Negatives: Nature and Evolution of Processes.
You will learn everything about photographic negatives in this downloadable PDF. As I have had a longtime interest with photo negatives via my former 40-year-old custom lab, I've perused this publication.
Like Burkphoto, I've kept my many 1000s of 35mm, 120 and large-format negatives and transparencies in Negafiles and like his negatives, are as fresh and clean as the day they were processed! Stored in thick archival boxes with proof sheets, they make viewing a pleasurable and a cost-effective way to store your negatives.
Someone suggested glassine envelopes which are good for short-term storage but they do yellow and the adhesives discolor and deteriorate. An alternative is to use clear storage envelopes made with "Mylar." A bit more expensive but handy.
Generally speaking, you want to avoid any material that is not archival: paper, glassine or "flexible" bags. Non-archival paper will yellow; glassine will also yellow and the adhesive will discolor (as mentioned earlier) while "flexible" bags such as sandwich or ziplock bags are flexible because they contain plasticizers which allow them to be flexible. "Mylar" storage products are stiff and rigid and the preferred way to store negatives or documents.
I speak with some experience as I also collect coins, stamps, comic books and men's magazines, all of which require archival storage to maintain their value and condition. Non-Mylar products may outgas and leave a greenish PVC (plasticizer) on the contents or worse. Keeping out air, maintaining proper storage temperatures and humidity are extremely important.
I also have had much experience with film materials and storage with my former 40-year long custom lab business which I retired from in 2008!
I also recommend
www.universityproducts.com" as I have buying and using their products since my custom lab days. You can Google other similar sources.
Another thing, you should check your negatives for any that were shot with nitrate film which has been known to physically deteriorate. Many early cinema films were shot on it and have partially or completely disappeared.
Be well all! Happy New Year. Ed