A newbie! A newbie!
Thanks for registering and thanks for your concern about proper storage of cels. There have been a number of threads in the past that have discussed this topic, and I can sum up the basic points briefly:
Cels are chemically unstable and should be stored in a way that allows them to vent fumes caused by the gradual aging of the acetate sheet. I use an archival storage bag (polypro or polyurethane) that's slit down two sides, then slip them into the sleeves of an art portfolio. Itoya Profolio is good and commonly available. This then is stood up like a book so that the weight of the contents does not press down on the ones on the bottom. (Other collectors have alternative methods, but the gist is not to have cels on the top or bottom of a pile.)
Microchamber paper is recommended by many curators to help absorb potentially harmful fumes. I keep a sheet or half sheet inside each cel bag, sometimes with a partial sheet of cel bag plastic to guard against it sticking to the cel paint. That's readily available from online collectors' supply sites and on eBay.
The storage climate should be kept relatively stable, without large swings in temperature or humidity. Generally, the cooler you keep cels, the longer they will stay in sharp condition. But if cels are kept in a climate-controlled situation, that should be sufficient. (We keep our house between 65-75 degrees F, and I have not seen any bad results in 15+ years.) Periodic inspection is a must, and cel bags that become dramatically puckered should be replaced, generally about every 3-5 years.
Sketches are more stable and less problematic, but they should be stored separately from the cels. I cut backing boards from cardstock, (available at craft stores in the scrapbooking area, usually in 12 x 12 pads) and interleave microchamber paper between them, one sheet to five white-paper sketches and one to three colored-paper sketches (because the colored paper is thought to be less stable than white paper). Then I place them inside polypro or polyurethane bags (Mylar is also fine, though pricy) and store them inside archival boxes made of acid-free buffered boards. They should stay in good shape indefnitely.
[And yeah I need to spend some time creating some pages in this forum that give links to some of these threads.... ]
I'll let other collectors suggest sources for the series that you mention. I know that Cowboy Bebop and Evangelion are both highly desired, and so you may need to lurk for a while looking for your best bargains. Mandarake is a logical auction site to watch here, though the finish prices can be daunting. Still, with many collectors now losing interest and dispersing their collections, you may well find some good deals by responding to these calls for offers. It's been a mostly supportive community, not without drama from time to time, but generally the common passion prevails for the art and the genre that the art made possible.
Good luck! And happy hunting!
