True. But MDO and CDX can both be made from younger trees and although they are more expensive they are much more durable due to being layers of wood as opposed

True. But MDO and CDX can both be made from younger trees and although they are more expensive they are much more durable due to being layers of wood as opposed to glued fibers. LVLs are another good example. Edit: For DIY projects never use MDF or OSB. These products are for production building and are very unforgiving for weekend projects. And dustier.