We do not recommend using nails to attach cork wall tiles. In our experience, nails create concentrated stress points in the cork, causing the tile to warp or buckle around the fastener.
For a permanent installation, we recommend using a contact adhesive or, for tiles with PSA backing, a peel-and-stick application. If you are concerned about using a permanent adhesive on your wall, we recommend screwing a thin piece of plywood — 1/8 in. (3mm) or 1/4 in. (6mm) — to the wall before application. This will allow the cork tiles to be removed without damaging the wall.