What is the best board (type of wood) for making signs?

I will purchase board and then cut it to size of sign. Need something that doesn't warp.

  • Are these painted signs or does the actual grain of the wood show?
    – mvr007
    Feb 26, 2017 at 20:18
  • Indoor or outdoor? Framed? Lettered how? You should some more specifics regarding your application.
    – bpedit
    Feb 26, 2017 at 20:37
  • Both indoor and outdoor. Painted or stained. Professional vinyl or stenciled
    – Sue
    Feb 26, 2017 at 22:16
  • @Sue if you are going to be painting these signs wouldn't plywood be sufficient? It's cheap, easy to work with, and readily available so that would be what I'd go with if I had to choose. So long as you buy a decent/quality plywood it shouldn't warp.
    – mvr007
    Feb 26, 2017 at 23:20
  • Definitely select an exterior grade of plywood for any outdoor signs (if you choose that material, which I probably would :) Even if well sealed and painted on all sides, an interior grade will be subject to delamination over time if exposed to the elements. Also, thin stock may be more subject to deforming. You'll want to choose the thickness proportional to the size. If you need more specifics you'll need to specify sizes and describe the applications.
    – scanny
    Feb 27, 2017 at 0:54

2 Answers 2


Since most of what you ave admitted to does not seem to be aimed a "wood" signs, particularly, I would suggest not using any type of wood.

There are durable, exterior-grade, paintable foams made explicitly for the sign-making trade. They can be routed for relief/3d signs but they don't have any tendency to rot or warp.

Of "woods", waterproof Medium Density Overlay (MDO) is probably the most suitable/consistent product. It's a lot heavier than the foams. It has a completely smooth/flat surface (unlike plywood.)


You have a number of choices here, many of which aren't wood-based.

Need something that doesn't warp.

In reality warping is one of the lesser concerns, with swelling and delamination from water intrusion and glue breakdown being more critical factors than the development of a slight bow.

Plywood seems like an obvious recommendation here but it's not as simple as that unfortunately. Plywood quality has been in decline for a long time now and woodworkers regularly complain that what's sold today is noticeably inferior to what was sold just 10 or 15 years ago. And I've seen evidence of this firsthand, with supposedly waterproof plywood (hardwood ply stamped WBP*) delaminating after just a few months of occasional exposure to water.

So if you want a sign that holds up well for a long time suggesting you buy exterior-grade plywood is no longer sufficient. You need to source the best quality exterior ply you can find, and that is probably going to be classed as marine-grade. This stuff is expensive so expect some sticker shock, but it is guaranteed to be waterproof and to withstand extremes of temperature (e.g. from direct strong sunlight).

For a sign that will be painted I think either marine-grade plywood or a waterproof/water-resistant version of MDF are your best options in terms of wood products. Note: the MDF must be sealed fully, that means both faces and all edges, and this is a good idea with any plywood also.

For a sign that features applied vinyl graphics arguably nothing wood-based is the ideal way to go but instead an engineered plastic, metal (e.g. honeycomb aluminium) or composite board material. These are actually made specifically for signage. These boards respond minimally to changes in temperature, not at all to changes in humidity and, in short, few wood products can compete in terms of stability and service life.

The aluminium or aluminium-faced composite boards are also worth considering for painted applications (no wood grain, yay!), but you will need to delve into how to prime aluminium properly prior to paint application. It's not technically any more difficult than priming most other metals but for best results specialised primers should be used.

*Water-and-boil-proof, an older classification for waterproof/water-resistant plywood.

  • If you are going to be doing a lot of signs going forward, it would be worth looking into MEDEX MDF, a brand of moisture resistent MDF, as well as MDO (Medium Density Overlay), which is a moisture resistent plywood with paintable faces saturated in phenolic resins. Both are very stable, exterior grade paintable products that are much more resistent to warping than typical exterior or marine grade plywoods. In the cabinet industry we use then in areas we know will be prone to getting wet. Feb 28, 2017 at 16:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.