Lacey Carbon Film Coated with a Continuous Layer of Ultrathin Carbon Film. Copper Grid, 400 mesh. The continuous ultrathin film on lacey film allows for the thinnest support film that still has adequate strength to withstand specimen preparation. The film (< 3 nm thick) lies across a carbon lacey film supported by a 400 mesh grid. The size of the holes in the lacey film differ widely from batch to batch but are generally in the range of ¼ µm to 5 µm, which gives the equivalent support of at least 6000 mesh grid. Specimen material lying over the covered holes can be imaged in the TEM with practically no interference from the carbon film supporting it. This product is ideal for looking at nanotubes, virus particles and other small particulate material.