If you're looking for a sign to go outdoors, wood is probably the first option that springs to mind. After all, people tend to enjoy the natural appearance of wood, and wood signs have been used for thousands of years. Of course, that might just be because humans haven't had PVC foam available for thousands of years. Now that it's an option, you'll want to strongly consider using it instead of going for wood.
The Moisture Issue
Probably the biggest problem with wooden signs is that they don't cope well with moisture. When it meets rain, snow, or simply moisture in the air, wood tends to swell, and that eventually leads to a weathered appearance that can make the sign look shabby and well past its prime. PVC foam isn't subject to the same problem. It is made using polyvinyl chloride and polyurea, providing a completely waterproof surface. You could submerge it underwater for a few days and it wouldn't show any signs of swelling or rotting. After poor weather, a PVC foam sign will look as good as it did the first day it went up.
The Temperature Issue
Okay, you probably already know that wood doesn't react well with moisture, but you might not be aware that wood signs also react poorly to changes in temperature. It's down to the fact that wood will naturally contract and expand when it encounters changes in temperature. Maybe you live in the Northern Territory and experience very little rain – your wooden sign will still suffer since it will expand during the hottest part of the day before contracting during the cool of the night. This leads to cracking and swelling. Again, it isn't a problem you'll need to worry about when you opt for foam PVC.
The Quality Issue
Something people often fail to consider when choosing between wood and foam PVC signs is that the wood used is very unlikely to be of good quality. Wood used for signs tends to be cut from new growth forests. The timber doesn't produce very wide boards, so they need to be glued together to create a sign, and this means that they will rot, split, cup, or warp more easily. Foam PVC is made under strict manufacturing guidelines, so high quality is dependable from piece to piece.
Wood signs might seem like the more upscale option, but it's smarter to go for foam PVC.