Demand on material properties of toner especially viscosity and elasticity are different depending on whether fusing is accomplished by contact or non-contact means. In roll fusing (contact fusing) toner particles are subjected to pressure and heat for dwell time dependent on the roll speed and nip length. The assembly of toner particles goes through compression while the layer is being heated. The molten particles are subjected to shear which results in changes in viscosity and elasticity. Subsequently as the toner particles on the media separate from the roller, they go through stretching at fairly high rates depending on the speed of the roller. Difficulties arise when heat is applied to the media, which leads over drying of the media and causes difficulties in media handling. The pressure distribution can cause image deformation and media curling. In non-contact fusing, radiant fusing, flash fusing, microwave fusing or steam fusing, toner assembly is subjected to intense heat without external shearing or stretching. Coalescence and spreading of the toner particles take place quickly and efficiently. Adhesion of toner to the media is expected to be stronger. Non-contact fusing is contrasted with contact fusing models and compared with experiments.