CAA: Christian Anime Alliance

Most of my manga is either out-of-print or a first edition, and are worth a lot of money (I've seen Kodocha go for $180 on ebay!), so I'm very careful with them. I'm scared that over time they will start to yellow.
Is there any ways to keep them from yellowing that anyone here would recomend?

Well, all things go bad eventually :/ Things break, paper disscolours and withers... The only thing I can actually think of is have them in a smoke-free environment. I notice that alot of things when you go on say, Ebay have them up for bid and say that. Smoke does help disscolour things and damage them faster. It's the only advice I have, really :/

Well...it depends on how much you want to spend. Generally, Tenshi is right, without unusual measures you can't do anything about them yellowing. While there is archival paper in existence intended to allow books to survive a very long time, your manga are made of cheaper high-acid paper, and will be prone to damage. The best ideas are to keep the books in a cool and dry environment, and if you are really concerned you could look into archival storage practices, generally involving anything from careful handling and sealing of the books to inert gas atmosphere (though I can't imagine you being able to do the latter). I suspect that putting the books in zip-lock bags and storing them in a cool-dry place would be your best option. Unfortunately, that prevents you from READING the manga, as reading them will wear the books out (though wearing gloves will help). To be honest, I wouldn't worry about it too much, making money off collectibles like this is a really hit-or-miss proposition, and I personally would much rather get use out of a good book than save it to sell.

You could scan in the pages and print them onto acid-free paper, in addition to keeping them on your hard drive.

.rai//

EDIT: Also, if you're seriously serious, you could look into one of those vacuum food sealers they sell in appliance stores. You would want to scan in your pages first, though. ^_~ A good one costs about $120-130 IIRC plus however many bags you need. That should keep them rather safe. If your manga is that rare and valuable, it would likely be worth it [and pretty cool at that].

.rai//

In addition to keeping them dry and in plastic as some have mentioned. Store them in a dark place. If anything makes acid paper yellow faster, its light, especially sunlight.

I have this spray can of stuff that's used to seal up my art and keep things from yellowing, at least I think it's meant to do that... Maybe something like that would work in a book?

Unfortunately most manga, first edition or not is printed on extremely cheap paper, similar to newsprint. The american editions are on slightly better and their paper has been improving as the market has become more mainstream, but cheap paper will yellow extremely quickly, a week or so for really cheap newspaper, about 5-7 years for decent paper. This is due to an acid content in cheaper papers they will degrade. The best way to protect paper from these effects are to handle it with gloves, keep it out of light and keep it out of air.