Stained molecules in the cell nucleus, the inner life of a synaptic cleft, or the surface of a floral leaf: Modern microscopes enable researchers to examine processes that are otherwise invisible and located in tiniest structures of organisms. However, the wide variety of available instruments and image editing techniques confront scientists with a challenge: Experiments from different laboratories are often impossible to reproduce and difficult to compare. The University of Freiburg initiative "Quality Assessment and Reproducibility for Instruments & Images in Light Microscopy" (QUAREP-LiMi) seeks to overcome this challenge. Since 2020, 350 experts from 29 countries have been working to standardize and better document microscopic imaging. The journal Nature Methods is devoting its December 2021 issue to the topic. In addition to studies, the issue features proposals and demands from researchers in an effort to develop and establish new quality standards.