Vessels used for photometric applications are subjected to special requirements and therefore differ from normal reaction vessels. Typically, cuvettes are used in photometers, while plates are used in plate readers, as the name suggests. However, there are numerous variants of both product types. They differ primarily in the material of which they are made and from which the specific light transmission results, and in the format, which in turn determines the sample throughput and the volume to be used. The following articles describe the different variants, when which type is used and which advantages and disadvantages exist. Decision criteria for the selection of the "correct" type are also given.