Natural Oak Veneered Doors Solid core   are solid from front to back. The typical solid core door is a mixture of wood particles glued together with heat, resins and hydraulic pressure to produce a uniform, consistent product.  Then they are edged and lipped in solid oak and finally veneered in a natural oak. This means that you will never get two doors the same. The beauty and one of the characteristics of  the natural oak veneer is that you will get a different shape of the grain and wide variant in depth of colour and shade.