I had asked about a bookshelf here before and got some good advice. And now that I have time to actually do it I'd like to ask some more questions if I could. It was going to be 36" wide overall, and about 45" tall. And I was wanting to use 5/8 inch plywood to save money, but so many people here said to go with 3/4. Seeing that you guys know more than me about this, I will go with your advice. But, if I do go with the 3/4 over the 5/8", do I still need to front frame and put a divider in the middle to support the weight? Other info: I was going to use runners to support the shelves.