Blockboard is often made from rectangular strips of softwood glued and bonded together
under high pressure. These strips are then sandwiched between a wood veneer, such as birch.
A single veneer on both sides is known as 3-ply. A double veneer on both sides is called 5-ply.
Blockboard is only suitable for interior work, as the glues used in its construction are not
waterproof. It is available in various thicknesses, including 12mm, 18mm, 22mm and 32mm.
The boards should be stored flat as blockboard can twist or warp.
If you decide to paint the surface, it is wise to paint both sides in order to equalise
the surface tensions, which will aid the shaping of the blockboard.