If you work in a laboratory on a daily basis, you will know that there is more to cleaning than meets the eye. Clean and, especially, residue-free laboratory glassware is essential to safe and successful work in the lab. The Dr. Weigert tutorial series “Laboratory glassware reprocessing” provides tips and recommendations for daily laboratory practice relating to cleaning and hygiene. This tutorial is about how to achieve maximum material preservation when cleaning sensitive laboratory utensils. Various sensitive materials are used in laboratories. These include objects made of pure aluminium as well as anodised laboratory utensils such as Kapsenberg caps and test plates. The anodised coating forms an additional layer of protection and enables colour coding by means of the dyed top oxide layer. Particularly gentle methods are required for automated reprocessing of these materials. In this tutorial, Dr. Weigert uses a cleaning experiment to show why it is important to choose the correct process parameters, and what the consequences of an incorrect cleaning program can be.