‘Fusing’ means to heat the freshly applied layer of wax to the one below it, or in the case of the first layer, to the board, or substrate that you are working on. Fusing ensures that the painting maintains its integrity and creates a strong surface. You can fuse with many different tools; the most common being the blow torch, iron and/or heat gun. Some artists use a light bulb for very gentle fuses. Each will give you a different texture/surface.