The high visibility vests that we offer can all undergo printing. Once a high visibility vest has been printed upon, tests must be carried to check whether the certified PSA still meets the requirements of the relevant safety class. At Engelbert Strauss , we therefore offer to print high visibility vests in signal colours. This avoids a downgrade in safety class. The following rules generally apply: According to the DGUV, the following effects can occur if a warning garment is changed. Excerpt from the section on protective clothing in the DGUV: “If a high visibility garment is changed by means of printing or addition of a badge, this may cause the fluorescent background material no longer meet the standards for minimum high visibility surface area and a high visibility vest (clothing class 2) may become a high visibility vest (clothing class 1), then the identification (pictogramme) would be wrong, the protective effect would be reduced and the best would longer be permitted for use in certain areas. Depending on the size of the overprint or the badge, and especially in the case of small sizes (S. S) of high visibility vests of clothing with trim material (non-fluorescent material), this may fall below the minimum requirement for visible surface.” (Excerpt from the DGUV)