Another possibility for reading spines of Lots of PBs; The "under-bed" one-high (rarely high enough for two-high?) wide and deep solid box. (Sometimes even teeny ball-"wheels" can fit on bottom - if carpet permits)
Of course too, many folks already have plans for blanket- other storage there, but seems to me it's a natural for something the size of PBs. If forced to an inconvenient box-size: Labels like Aa - Az(imov), etc. can sometimes suffice for the lack of instant display of all the titles.
If floors are bare, and you use wood-boxes - don't forget those Teflon (or T-like) slider thingies for heavy objects: 4 of those on a Big underbed wood box full of 100# ... might slide out pretty effortlessly.
Lastly, you can hunt for local (cardboard) boxmakers and specify the "burst strength" etc. (lots of lectronic UPS experience here) and get nice clean and serviceable boxes close to a specified shape. What's your time worth, Oh non-handyman?
Ashton