We recommend starting with a commonly used grid type: 300 mesh grid spacing; either 2/2 or 1.2/1.3 hole spacing; manufactured by Quantifoil or C-Flat. Note that there can be a long lead time on these grids, so order in advance!
Ted Pella (Quantifoil only)
SPI (Quantifoil only)
N.B. These suppliers are based in the USA
Autogrid boxes can be ordered from FEI via SFR.