To access information hidden beneath the surface of a sample one way is to slice up the sample and look at the individual sections with a microscope. This is even possible in 3D – when images of serial sections are reconstructed into a virtual volume. This approach, created for neuroscience investigations, has become known as array tomography and can be applied to light or electron microscopy, but also for corelating the two imaging modes (CLEM). Participants will learn how samples are prepared by embedding in resin, how to trim and section and finally how to image sections and section arrays. A short excursion into image processing, 3D reconstruction and visualization of results will also be offered.