Corrosion casting is the technique by which a solid, negative replica is created from a hollow anatomical structure and liberated from its surrounding tissues. For centuries, different types of hardening substances have been developed to create such casts, but nowadays, thermosetting polymers are mostly used as casting medium. Although the principle and initial set‐up are relatively easy, producing high‐quality casts that serve their intended purpose can be quite challenging. This paper evaluates some of the more popular casting resins that are currently available and provides a step‐by‐step overview of the corrosion casting procedure, including surface casts of anatomical structures. Hurdles and pitfalls are discussed, along with possible solutions to circumvent them, based on personal experience by the authors.

Plastination was a game-changing invention for macroscopic anatomical preparation.The method yielded dry, odourless, tangible and durable specimens which allowed new exhibition and teaching set-ups and paved the way for sophisticated preparations and spectacular positioning of specimens. Despite the impact of the new method, there have been similar techniques in place before. Exsiccation techniques, polymer embeddings and specimen impregnation with hardening substances were earlier methods which already included the main concepts that were later combined and refined in plastination. S10 silicone plastination, the technique most commonly known and applied, was followed by plastination methods suitable for research and sectional anatomy teaching. Numerous variations of sheet plastination techniques allow research applications and new ways of presenting topographic relations and mesoscopic insights. Besides the development of plastination techniques in sensu stricto, related techniques had a renaissance with new applications and developments, including corrosion casting and diaphonization methods. This brief review shall provide a historical context of plastination including some anecdotal spotlights on the ideas and innovations that lead to nowadays plastination techniques.

Vacuum forced tissue impregnation is the signature step of the plastination process.It requires polymers with a low vapour pressure, low viscosity and a long pot life.Plastination polymers are a compromise between these mandatory requirements on the one hand and various secondary demands such as specimen stability, resistance to UV light and defined light refraction index on the other hand. Combining different polymers in one plastinate instead of using one plastination polymer alone can result in improved specimens for exhibitions and teaching including hands-on use for students. The aim of this study was to assess the range of possible sheet plastinate modifications and how the resulting multiple polymer plastinates can fulfil the secondary requirements of user-friendly plastinates. Adding sub-steps of tissue impregnation and processing to the standard plastination protocol allows combining different polymer properties including the use of substances which are not suitable for conventional plastination as such but have better properties than plastination polymers. Advantages like resistance to UV light and mechanical stability can be combined and characteristic disadvantages of plastination polymers can be avoided.Acrylic protection layers (APL) offer a complete protection of the specimen in combination with advanced presentation possibilities and the option of completely refurbishing valuable specimens. Hybrid sheet plastinates provide lower preparation cost and polymer-tissue interactions for an improved visualization of fat, nerves and brain tissue. Selective impregnation is a promising approach for the clearer differentiation of various structures and tissue types.

With classical sheet plastination techniques such as E12, the level and thickness of the freeze-cut sections decide on what is visible in the final sheet plastinated sections. However, there are other plastination techniques available where we can look for specific anatomical structures through the thickness of the tissue. These techniques include sectioning and grinding of plastinated tissue blocks or thick slices. The ultra-thin E12 technique, unlike the classic E12 technique, starts with the plastination of a large tissue block. High temperatures (30-60°C) facilitate the vacuum-forced impregnation by decreasing the viscosity of the E12 and increasing the vapour pressure of the intermediary solvent. By sectioning the cured tissue block with a diamond band saw plastinated sections with a thickness of <300 μm can be obtained. The thickness of plastinated sections can be further reduced by grinding. Resulting sections of <100 µm are suitable for histological staining and microscopic studies.Anatomical structures of interest in thick plastinate slices can be followed by variable manual grinding in a method referred to as Tissue Tracing Technique (TTT). In addition, the tissue thickness can be adapted to the transparency or darkness of tissue types in different regions of the same plastinated section. The aim of this study was to evaluate the advantages of techniques based on sectioning and grinding of plastinated tissue (E12 ultra-thin and TTT) compared to conventional sheet-forming techniques (E12). K E Y W O R D Seducation, plastination, sectional anatomy | 565 SORA et Al.

Dear colleagues, Forty years after the term plastination was introduced, this special issue is a status report of the developments in plastination and a look back on the evolution of this technique. When Gunther von Hagen's first plastination attempts ended in rather disappointing results, he was probably the only person who imagined that this technique would revolutionize anatomical preparation and pave the way to countless applications in teaching, anatomical exhibitions and research projects.Besides presenting these applications and some of the research done with and about plastination, this special issue is mainly focusing on the technical methods as such. Therefore, articles include easyto-follow "cookbook style" instructions for plastination methods:The two established silicone plastination methods ("cold S10"and "room temperature" technique) are explained in detail, describing the basic mechanisms of vacuum-forced impregnation and silicone polymer components. Separate short technical descriptions are dedicated to specific aspects of silicone plastination like the coloration of specimens and the plastination of extremely large plastinates. Sheet plastination includes several variations and modifications.Conventional epoxy E12, polyester P40, ultra-thin epoxy cutting and grinding techniques and multiple polymer plastinates follow different approaches, lead to different results and are each discussed in separate articles.In addition to plastination in the narrow sense, related methods like the corrosion casting technique had a renaissance through its close link to plastination, while the rather new technique of 3Dprinting will play a more important role for producing life-like anatomical specimens in the future. Glycerine clearing of specimens is another related method for presenting insights into the anatomy described in this special issue. Authenticity will become more and more important in education, as virtual presentations replace real experiences in all parts of life. Plastination is the ideal method for providing authentic, trustworthy insights and sparking interest in life sciences. No matter what technique, plastinates should always try to reveal the beauty and fascination of the anatomy. The whole complexity of a body can only be understood completely by looking at a real specimen directly. Plastinates can facilitate a holistic understanding of the morphology by connecting the different body "systems" and at the same time closing the gap between histology and gross anatomy. Authentic and aesthetic insights are necessary not only in teaching of anatomy but also in schools and in lay education. Understanding the morphological side of the "miracle life" helps create respect towards nature and every living being. You cannot get the same authentic insights from images, books, animations or other learning tools; however, plastinates can fill this void. Take the facts in your own hands, look and see for yourself (Louis Agassiz)I would like to thank all authors who contributed to this special issue. Special...