It is preferred that the polyester composition should comprise a majority of a polyalkylene terephthalate polymers or PEN polymers, more preferably in an amount of at least 80 wt. %, most preferably at least 95 wt. %, based on the weight of polymers (excluding fillers, compounds, inorganic compounds or particles, fibers, impact modifiers, or other polymers which may form a discontinuous phase).