Walnut wood

I'm making the 12 steps 3 sun Japanese puzzle box. this time these are walnut wood and natural wood types. walnut wood of top and bottom panels are not solid wood board. the sliced walnut wood is pasted on the plywood. If it were made from solid wood, the top panel would shrink in countries with lower humidity than Japan. because, the top panel is very thin (about 3mm) and not fixed, it is susceptible to the influence of outside air.