Whenever buying Pine & Oak Furniture it's always a good idea to mindful of the quality of your purchase.
Realistically look out for the words Solid Wood. The more detail the retailer shows on an item the better. So in the case of Bookcases the shelves, backs should all be solid wood if your paying top doller.
Naturally if your buying from cheaper sources then you have accept that some of MDF in the bookcase.
