I've always used Dragon Shield for sleeving my decks and recently I've noticed the sleeves come slightly curved in the box. This means when I sleeve my decks they sometimes slide and fall on the floor. I've tried stacking books on them to make them stay flat but it doesn't help much as they never stay. I was just wondering whether anyone else had this problem and what they did about it, I noticed that putting them in a particularly tight box can help, but it also sometimes bends the cards which I don't want.
This answer comes from personal experiences I've had with using Dragon Shield sleeves, so it shouldn't be taken as fact, since the sleeves from different batches can vary.
First things first, I'd recommend always using Matte sleeves, for several reasons:
- I find them much easier to shuffle;
- They don't get as grimy as smooth sleeves;
- They don't tear as easily as smooth sleeves;
- They don't get as curved as smooth sleeves.
For the specific problem of curved sleeves, I've tried many solutions over the years, and some seemed to work better than others.
One thing that worked best for me for straightening both sleeves and cards was to weight them down with a couple heavy books over a warm surface. I usually use a hair drier to warm up a metal surface, and then keeping it warm while the cards and/or sleeves are being weighted down. This works great for a couple cards/sleeves, but it's a lot of work for a whole deck.
Also, sleeving the cards with a "perfect size/fit" (the inner sleeves that go inside the outer sleeves) makes them slightly less bendy, which could help in straightening out your outer sleeves.
As you said, storing the whole (preferably double-)sleeved deck in a tight fitting deckbox also helps with straightening out both sleeves and cards.
P.S.: To whomever it may concern, I am thinking of opening this answer as a community wiki, so everyone can chip in with their own experiences on the subject. What do you guys think?