Free shipping on our plein aire panels. Marine grade 4mm mahogany finely sanded and sealed with shellac. 6" x 8", quantity five. This wood has an open grain that provides a bit of texture to capture the artist's paint. Most veneers are only 1/32 of an inch, and use cheap products as a core. Because these mahogany panels are used for boat-building, they need to have strength and stability. All three layers are void-free okoume mahogany, both sides are sound, though one side of these panels may be prettier than the other. We shellac and sand both both sides and edges of the panels with a wax-free shellac. So you receive them ready-to-use as a painting support.