In this paper we give a model based proof of the fact that it is possible to grow from the melt in a vacuum by EFG method single crystal filament and sheet with pre-established piece-wise constant diameter cross-section and constant thicknesses d 1 ,d 2 ,...,d n , respectively of lengths l 1 ,l 2 ,...,l n , changing adequately during the growth, the melt temperature T m at the meniscus basis and the pulling rate v.