This collection of 99 high resolution TEM/SEM electron microscope images of cell division, herpes, HIV & adeno-virus, clostridium, giardia, chomosomes, mitochondria, taste buds, blood, cardiac muscle, skin, & more.
The resolution of these images is high enough to print a poster. The file format, PhotoCD, uses lossless compression but is over 20 years old. Not all image file editors may be able to support it.