A bulk substrate for stretchable electronics. The bulk substrate is manufactured with a process that forms a soft-elastic region of the bulk substrate. The soft-elastic region includes a strain capacity of greater than or equal to 25% and a first Young's modulus below 10% of a maximum local modulus of the bulk substrate. The process also forms a stiff-elastic region of the bulk substrate. The stiff-elastic region includes a strain capacity of less than or equal to 5% and a second Young's modulus greater than 10% of the maximum local modulus of the bulk substrate.