I did a big bookcase project using those metal standards you bolt to the wall. you can go to the Sagulator to see about width between brackets based on what you expect to put on the shelves. But what if you are stuck w/ a bigger span than the Sagulator tells you will work? Or if you want to use plywood or pine instead of some expensive hardwood? Remember that attaching a second board perpendicular to the front (like a lip, but on the bottom) of the shelf will strengthen it quite a bit--that's not reflected in the Sagulator's calculations. Here's how it works: you cut your 3/4-inch-thick plywood to the length you want, and to the depth you want minus 3/4 inches. Then you get a narrow piece of wood--maybe a 1x2--and cut it to the same length as the shelf. You lay the 1x2 against the front edge, so it points down. You apply a solid smear of wood glue between them, and you nail it in place. (clamp or strap it if you can to improve the glue bond). Maybe you can use a 1x1, which would probably be the same width as your shelf itself, but it wouldn't add as much strength as a 1x2. Sometimes this reinforcing wood is attached to the UNDERSIDE of the shelf right at the front; again, it's glued and perhaps screwed (since the screw head won't be visible), to keep it very snug against the shelf. Because this board is perpendicular to the shelf, it'll keep it from sagging (think about iti--ever tried to bend a 1x2 sideways along the wide face?) You can often reinforce w/ a strip of L-angle metal; it needs to be toward the front and it isn't as attractive as a strip of wood. Stronger, maybe but not as pretty. You can use something a bit smaller than you might need if you use wood, which would mean it impinges on your storage space less.. If you're worried about your ability to clamp or strap the wood to get a good blue bond, you could use the metal L-angles, and then on the front of the L-angle, attach a strip of lattice. One advantage of attaching that wood to the front of the shelf is that it will cover the raw cut edge of the plywood. But if you choose the L-angle idea, you can get the iron-on edge banding to finish the fronts. They make a snifty tool to trim the edges of the edgebanding. That's what I did, and the shelves look great. Plywood is the most economical way to get shelves the side you want. Trying to buy boards the exact width is more expensive than paying the lumber yard to cut the wood. I personally would avoid Home Depot bcs in my area, they won't promise to cut to exact size; I go to a lumber yard that will. Also, I've had people tell me this, and then tell me it wasn't true: When you have your plywood cut to size, be sure the surface grain of the top layer of plywood is running the LONG way on the shelf. NOT the short way; it'll bow more easily that way. Maybe it's not true on the 3/4 plywood, but I've seen this be a problem on 1/2-inch plywood, and I wouldn't take a chance on any other width. Another thought: remember that those brackets themselves take up space from the shelf below, so that front drop-down lip won't affect THAT much of your storage space. And, you might not want to have that many of those brackets across the span, just because they get in the way. So putting one on every stud might be a royal pain. I know for our bookshelves, we went w/ the outside dimension we could possibly get. OH, and to make it so the shelves would touch the wall between the standards, I cut out a notch where the standards would go. Next time, I'll get a hole saw for my drill and cut out a semi-circle at that spot; it'll be much easier. The 90-degree turns were a PITA. Feel free to ask me any more questions, either here on this thread or by e-mail. Here is a link that might be useful: Sagulator

That is not going to be an easy project. Especially if you are planning to do a contrasting color on the back panel. A professional outcome would likely require disassembling the shelves. You need to sand all of it carefully or the paint will scratch off as soon as you put all of those things back in it. And it should be sprayed, not brushed. It’s a beautiful shelving unit. I would try restyling the pieces that go in it before trying to paint it. If you really don’t like it, it’s probably easier to replace it with something else. But it looks like someone payed a pretty penny for it !

Do you want real book shelves or shelves on which you will place a few books plus decorative things? When I see most shelves here on Houzz, it is with only a few books and lots of stuff, following the “rule” of 1/3s, or some such thing. If you want a place to have your books lined up for use (not spine to wall, or arranged according to color) I suggest good, solid book shelves, purpose built for your space. Floor to ceiling. But having books of all kinds, paper backs, coffee table style books, hard backed books that close to your kitchen and dining room, isn’t terribly good for your books. They can absorb odors. If you want shelving for more decorative purposes, I get it. The ones suggested here will work.

We used the phantom lighting system for our bookshelves. It works great. The led strip on each shelf is mounted on the underside of the outside edge. Shelves remain adjustable. https://www.phantomlighting.com/