Here's an image of 3M micropore tape, magnified 200 times:
It's a stacked image, layered from 21 snapshots taken at different focal depths. The large coffin-shaped gap indicated by the red arrow is about 119 μm long, and roughly 39 μm across, at its widest point.
By comparison, a Trichoderma spore is less than 5 μm long, and most bacteria are barely half that.
So, if you're using the stuff (as I sometimes do) to cover GE holes in spawn jars, apply 3 or 4 layers.
