The thickness of the gold film is 13±1 nm and the biaxial pre-strains in the substrates are 200%. SEM images (top panel low resolution, bottom panel high resolution) of gold film on a substrate under sequential relaxation with εf1 = 67% and εf2 = 3% (a), 20% (b), 50% (c) and 67% (d). SEM images (top panel low resolution, bottom panel high resolution) of gold film on a substrate under simultaneous relaxation with εf1 =εf2 = 5% (e), 30% (f), 50% (g) and 67% (h). The scale bars are 10 μm in top panels and 2 μm in bottom panels of (a)–(h).