Hi all, I'm looking for some ideas on what to use to border the perimeter of a dio with a sloping grade. Rear portion will be fairly level with the two flanks slightly sloping down to the front edge.
I've tried balsa/bass wood sheeting but the thickness I'm looking to use is just too thin to get a good 45 deg. miter joint. Butt joints look amateurish imo.
Does anyone have any ideas or a better process to get that good 45?
Any help or ideas would be greatly appreciated.

If you can't get a good 45 because of the thickness, but butt joints are too bush league, you may try a technique like dovetail joinery. It is a nice, and relatively simple choice that looks very nice and would be pretty easy in balsa wood.

May I suggest using plastic with butt joints fill and sand the paint the plastic a neutral or black color.

Ditto on the thin plastic, I bought some for my next diorama with variable height sides (after seeing some excellent examples on the interweb done that way)

You could do a miter joint but you would need to reinforce the corner from the inside with a wooden block. Kind of like this:



I've done it several times and it has worked very well. I cut the block slightly shorter than the top edge of the wood so that I can cover it with ground work.

A lot will depend on what you are using for your ground material, and how deep it will be. For instance, if you are using anything wet, like Celluclay, it will warp your wood in every direction, even if you seal your wood . Even a thin layer on top of styrofoam will cause warping. Best to use Pine or Spruce at least 1/8 inch thick. You can find an inexpensive mitre box and saw for around $20 at home depot/hardware stores.

I go with plastic card and just box end it together. Sand the ends smoth and paint to color. wont warp and is strong enough to hold a plaster type ground cover. If you want, drag a saw blade side ways to give it a wood grain effect.

Thanks all, for the advice posted. Some good tips.
On this, the problem worked itself out. The 45 wasn't so much the issue as a clean edge was for mating the pieces. I normally use a groundwork putty like Das Pronto when I use the higher wood sides, but have been hit by warpage from celluclay before.
I've tried the plastic route and it has worked well.
I just tried a hybrid from scraps using plastic card and some balsa as a veneer. We'll see how that works out.
Thanks again for the mind work. If I ever figure out how to post pics, I'll be sure to share.