QUANTIFOIL is a perforated support foil with pre-defined hole size, shape and arrangement that has advantages in electron microscopy (EM) or low-energy electron point source (LEEPS) when compared with conventional holey film. QUANTIFOIL with circular holes is used in cryo-electron tomographic reconstruction. The roundness of the holes is advantageous with respect to the formation of an ice layer of constant thickness. May be preferred over R 1.2/1.3, when an increased tolerance with respect to the position of beam, and a larger beam diameter are desired, such as in the case of automated image aquisition. Hole size is 1 µm. Space between holes is 3 µm. Center to center is 4 µm. Smaller holes are designed for magnifications of 50,000x or higher.