Historic negatives, best stored in paper envelopes or polyester pockets?

A question for the photo archivists out there.

Over the past couple of years I have amassed a collection of negatives spanning from the 1890's to the 1970s. It includes both glass and cellulose based negs. There are a couple of cellulose nitrate negatives, but I try to limit the acquisition of these as much as I can. Thankfully there were parts of the world slow to adopt film based processes, and continued to use glass plates upto the advent of safety film. I love the glass plate negatives. Some from 100 years ago have aged very little, with just slight traces around the edges of the plate.

I am at a point where I need to devise proper storage for the collection. Many of the negatives are sitting in their original envelopes, and it's time to move them into longer term archival housing. I have a good grasp of how to handle the glass plates; in 4 flap acid free envelopes, standing on their edges in foam lined acid free boxes. However I'm on the fence as to how to approach the cellulose negs. Some of the collections from the 1950s have an acid odour. I believe they are in the early stages of vinegar syndrome. Though the negatives have no visible signs of damage.

Most of the cellulose negatives are sheet film. Some are cut medium format or 35mm frames. A few are 35mm strips. I have contact prints of them all in a binder, so I will not require viewing of the negs. Though I will be accessing the negatives to print or scan.

The two storage methods I am considering are either, Secol polyester sleeves, which I know many photographers like: https://www.secol.co.uk/products/slides__films_and_negatives_stor?sc=0.
–– or Perma Dur buffered paper envelopes: http://www.preservationequipment.com/Catalogue/Archival-Storage/Envelopes/Photo-Storage-Envelopes-PermaDur-Buffered

I recall reading somewhere that it is best to let older negatives "breathe", therefore I am leaning towards the paper envelopes. My question to the experts out there, is this true? Is it adventagous to use paper, or is the polyester fine?
Would the buffer incorporated into the above envelopes help to neutralize/slow the vinegar syndrome, or should it be avoided? Would the (much less expensive) acid free glassine envelopes suffice? http://www.preservationequipment.com/Catalogue/Archival-Storage/Envelopes/Glassine-Envelopes

I see myself as a custodian of this material. It would be nice if I could set up the collection to live another 60 to 100 years.

I look forward to any opinions or suggestions.

The United States National Park Service has a Museum Handbook https://www.nps.gov/museum/publications/handbook.html

The Handbook's Appendix M, Management of Cellulose Nitrate and Cellulose Ester Film, should be useful.

If you have trouble finding the appendix, let me know and I will send you a copy.

i regularly submit negatives to archives
for "modern" film you want "non buffered thumb tabbed envelopes"
for non safety film i would email nedcc.org

I believe that the Library of Congress uses glassine envelopes and sleeves. I would consider them the go to authority on negative storage.

Thanks for all of your replies.

I am going to go with what is in the National Park Museum Handbook, an excellent document particularly about cellulose nitrate film; https://www.nps.gov/museum/publications/MHI/AppendM.pdf. It recommends buffered envelopes – "Use buffered sleeves for cellulose nitrate and for black-and-white cellulose ester film, but use unbuffered sleeves for all color film."
Makes sense, to help combat the acidity which naturally leaches from the negative substrate as these older negs age.

I'm also going to add a pack or two of silica gel to the negative storage boxes to help keep humidity and moisture to a minimum, along with a sheet or two of MicroChamber molecular sieve sheets, which "...simply capture gaseous byproducts that speed deterioration..."

Wish I had a cold storage facility to store the boxes in. Don't think my family would appreciate aging negs in the freezer next to the ice cream.