Microscopic examination of surfaces developed in tantalum ribbons on heat treatment in vacuum shows a dependency of surface structure on whether a.c. or d.c. supply is used for the heating current. Further modification of surface structure results due to recrystallization over a temperature range of 1900°K to 2500°K. Grain growth is shown to increase exponentially with the temperature. An optimum amount of cold working of the samples before heat treatment results in exaggerated grain growth yielding large single crystals.