Blockboard is made up of a core of softwood strips. These strips may be up to about 25mm wide. The strips are placed edge to edge and sandwiched between veneers of hardwood. The sandwich is then glued under high pressure. Blockboard is not suitable for outdoor use because the glues used are interior glues. When using blockboard to make such things as doors or tables, it is important to ensure that the core runs lengthways in order to achieve maximum strength. Blockboard may be used to make shelves, doors, paneling and partitions. Superior Brands of Century Board, Green Board, Ecotec Board, etc.