Collecting VGM-Anime-ecc., how do you place our collection?

[depa]

I don't find a post that speaks accurately about how is the best/accurate solution to preserve our CDs? surely most of us use polypropylene envelopes to protect disc from sun's rays and dust; I've seen collectors use envelopes with adhesive strip, others envelope partially open at the top or at the bottom (probably to give breath at the paper?) don't know how is better but it's not the matter.
My real question is how to place our collection into a wall library.
Is it better to put our discs side by side (beautiful solution but it takes too much space), or in colums (not so beautiful but it takes less space)? If you put them in colums, which direction do you use? the back cover towards the bottom or towards the top?
I ask this since I've read somewhere that putting CDs in colums with back covers towards the bottom bring booklets (or obis if put inside) pushing the four plastic teeth and after some years they surely have the teeth mark on them, so many others ask it's better to have back cover towards the top since there is no booklet rubbing on plastic teeth and it's near impossible CD fall down if round teeth are fine.
And what's about obis? Which is the best solution to preserve them? Do you put flat? Or is it better they wrap around the case?