In the good old days of highly skilled craftsman only real wood was considered for any trim work or for furniture building. Over the years many wood substitutes and plastics have bee introduced for trim and furniture building. Terms like particle board and even plywood have been four letter words for the true woodworker and no quality furniture builder would even consider using anything but good old natural wood for the top line of furniture. Things have changed recently although good quality furniture like end tables and coat racks are still made from natural wood some of the new wood substitutes are actually better than wood in certain cases.
I am not sure anyone actually enjoys painting the outside of their house especially when it comes to painting intricate trim, up the ladder down the ladder move the ladder repeat. Well today PVC (polyvinyl chloride) is a great substitute it will not absorb water or rot and can be purchased with a pressed in wood grain look if your trim color is white you can simply attach the PVC boards and you are done no painting no paint peeling no repainting every few years no need to replace do to rot ever the only two drawbacks are price and that PVC will contact and expand more than wood. The price factor is more than compensated for by reduced maintenance costs and painting.
Engineered woods we are all familiar with like plywood and OSB board have been used for many years and have their place but a new engineered wood or compressed fiberboard is made from wood fibers and a rein that is heated and compressed this procedure basically waterproofs the wood making it ideal for exterior trim however it still needs to be painted but is far better than traditional Cedar or Pine for exterior trim work.
A combination of wood and plastic is evident in the new composite these are created by utilizing scrap wood fibers and adding plastics and a bonding resin this makes the composite very strong waterproof and it can be machine just like traditional wood with a router or sanded to fit just like traditional wood trim. The big drawback to any of these engineered type of wood substitutes is they do not convey the feel of wood the natural wood grains cannot be reproduced but if you are painting the trim anyways it will not mater for fine furniture natural wood is still the way to go.
