I've been asked to build a display map of the world made out of wood. The idea would be to have a 3'x6' flat background with continents on top to hang. I'm leaning toward doing 6 x 1/2 inch poplar for the background and doing a few different wood stains to individual boards or using greys to get more of a recovered barnwood look. I'm also considering vertical shiplap but I don't know if the gaps will throw off the aesthetic.

For the continents I'm debating between doing something similar to the poplar (glue boards together and hand plane then stain) or going with a plywood.

I've done each of the pieces here on individual projects (shiplap, hand planed glued boards, jigsaw, etc.) but I don't have a lot of experience with the layering aspect that the continents bring and I think the jigsaw work is going to be time consuming. I also want the continents to be distinct from the background but for it to also fit together aesthetically. Any recommendations on something like this?

From your description, sounds like the continents will be the focus of the map? If that is the case, I think a more neutral backround may work better? And maybe less time consuming.

Rather than using boards for the backround, I would go directly to a sheet product, be it plywood (1/2"?) or MDF (MDF stands for 'medium density fiberboard', but actually comes in three different weights/densities; heavy, medium, and ultra lite. Watch the dust when cutting, it's bad, but the surface paints well, use two coats of primer).

I think cutting a sheet and painting it (remember to do both sides to reduce bowing) would leave you more time to do the time consuming task like shaping the continents. Would you do the backround in a blue/ocean color? Or is there another goal for the backround?

I like to have the land as a lighter color of stained wood, and the water as a darker color with a blue or gray tint to it. Similar to the wooden lake signs they make:

Thanks for the suggestion!

The idea right now is to do a recovered barn wood look on the background. Basically a few blacks/greys on the background, rub with a rag to blend it thoroughly and white wash it with diluted paint. The continents would either be a lighter stain or possibly painted.

I like the idea of going with a plywood. It would make life a lot simpler and I think the grey stain would look good. Lighter stains on plywood can sometimes wind up looking almost psychedelic as the grain will hold darker but probably not with a stain so dark.