Collecting Keeping Cards in Top Condition

[Empoleon_master]

In the state that I live in the weather this past month has been so random that I've had to turn on the AC the night after it was cold enough to make me consider putting on a sweater to bathe, this is obviously bad for cards as I inevitably found out that a bunch of mine have curled out from the middle of them, even inside elite trainer boxes. The weather can be warm and humid one day and I need to wear boots to go down stairs cold the next night, so if anyone has any tips for keeping cards from curling and getting damaged in these conditions please post them here, I really don't want my cards that I use for competitions getting damaged.

 

[Purrloin]

I prevent bending for my Ultra Rares primarily with a sleeve + top loader combo, though if these are cards you'll be using often in competitions, it might get cumbersome taking them in and out.

Alternatively for holos I use 9-card binder pages and place two cards per slot back to back (i.e. which also lets you see the rear card through the back of the page). From my experience this has prevented most, if not all of my holos from bending for quite a while now.

Another method that I've heard (but haven't tried) is placing the foil card inside a normal sleeve with two non-foil cards (e.g. commons) in front and behind it. Downside being, of course, you can't really see the card.

 

[GrandPanacea]

I've got an Ultimate Guard 2x2 binder for my cards. Sleeve them then stick them in the slot. Keeps them nice and flat. I've been playin' TCGs for years now, and Magic is really bad for this, and I have similar sounding weather, so I've learned what to do.

 

[Elbow]

For all cards, keep them close together. Even deck cards. I keep all of my card arranged by set and number and tightly packed (but not impossible to take out) in 800ct card rows. This prevents the weather to affect the cards too much. I would also keep the box or whatever you use covered with a lid or some type of top.
Also, sleeve any other important card and still pack them tightly. I do this for all EXs, SRs, and some holos and rares with penny sleeves or high quality sleeves. This prevents those cards from curling all together and won't stick for any reason. Binders or Toploaders help with this as well.