Re: Built-in Bookshelf Advice
Shelves do not need to be captive, regardless of the cabinet being a built in or free standing, you just have to make sure that the unit is built to accommodate whichever style shelf you choose (fixed or adjustable ).
It is your choice how you build the cabinet (backed or backless ), depending on the wall you're going up against. What you will need to be wary of is that a back adds strength and stability to the cabinet, so unless you'll be affixing the cabinet to the wall, put a back on it. Most "built-in" cabinets are actually freestanding cabinets slid into a niche, then trimmed around the front to tie it into the opening, hence most have backs for structural rigidity. What you can do instead is to put a cleat at the top and mid-point of the cabinet, then you attach the cabinet to the wall with these cleats, thereby giving you a sturdy backless cabinet.
I've never used plywood thicker than 1/4" for a back on any bookshelf, it just isn't necessary.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!