The present third volume of the "Handbook of Chemical Analysis of Textile Fibers" continues from the first volume (qualitative and quantitative fiber analysis) and the second volume (compilation of all textile fibers and their testing) by addressing fiber deposits and inclusions as well as chemically modified fibers. This volume covers, on one hand, natural fiber accompaniments that play a role in the textile finishing process, and on the other hand, novel effects that arise from finishing measures; the latter are summarized under the term "special treatments." The area outlined here has grown so significantly in recent decades that it has proven impossible to present the entire subject comprehensively in a single volume. Therefore, the originally planned division of the entire work had to be abandoned, and the material was distributed across multiple volumes.