The authors report a method to synthesize high-quality graphene by surface segregation and substrate transfer. Graphene was segregated from Ni surfaces under ambient pressure by dissolving carbon in Ni at high temperatures followed by cooling at different rates. The cooling rate significantly affected the thickness and quality of the graphene films, with medium cooling rates producing the highest quality crystalline structure and well-controlled thicknesses. The graphene films were transferred to insulating substrates using wet etching and maintained their high quality as confirmed by electron microscopy and Raman spectroscopy. The study also explored the effects of H2 in the growth atmosphere and substrate roughness on the uniformity of graphene layers. The results suggest that controlled cooling rates during surface segregation can offer a high-quality and low-cost synthesis approach for graphene as a practical electronic material.The authors report a method to synthesize high-quality graphene by surface segregation and substrate transfer. Graphene was segregated from Ni surfaces under ambient pressure by dissolving carbon in Ni at high temperatures followed by cooling at different rates. The cooling rate significantly affected the thickness and quality of the graphene films, with medium cooling rates producing the highest quality crystalline structure and well-controlled thicknesses. The graphene films were transferred to insulating substrates using wet etching and maintained their high quality as confirmed by electron microscopy and Raman spectroscopy. The study also explored the effects of H2 in the growth atmosphere and substrate roughness on the uniformity of graphene layers. The results suggest that controlled cooling rates during surface segregation can offer a high-quality and low-cost synthesis approach for graphene as a practical electronic material.