Historically, invertebrate organisms were much more difficult to incorporate into natural history collections for teaching and exhibition than were vertebrates. The traditional method of displaying invertebrates was to “fix” them in preservative fluid and suspend them in glass jars. Original colors faded and soft-bodied specimens simply collapsed. Addressing the need for teaching materials, German glass blower Leopold Blaschka (1822–1895) and his son Rudolph Blaschka (1857–1939) developed techniques to create biologically accurate models made of glass. For 30 years the Blaschkas made and sold thousands of glass models to universities and museums around the world, allowing students and the public to see these creatures for the first time in their original shapes, colors and beauty.
Over time, glass models were replaced by less expensive plaster and wax models, which had become more refined and could be easily mass produced, shipped, stored and handled. The early and especially accurate Blaschka glass models have now become revered as rare, beautiful, and masterful works of art.
Blaschka glass models were made using standard lampworking (also known as flameworking) tools, equipment and techniques. A workbench of the period was equipped with a foot-powered bellows supplying air to a torch tip passing over a paraffin-fueled lamp wick. This was used to fashion individual pieces as well as to assemble the finished model. Fusing colored glass enamels was also done in the flame, as was some annealing.
The Blaschkas spent months of every year making large quantities of the smaller elements for the compositions. Ensuing months were spent painting, gluing, finishing and assembling. Leopold preferred lampworking while Rudolph was a fast and skilled painter. Final assemblies were done by both men. Lastly, these delicate models were packed and shipped world-wide.
Today’s glass-blowing shops employ many of the old techniques with the addition of some modern equipment. Tracy Drier, a collaborator on this project, runs the Scientific Glassblowing workshop in the Department of Chemistry.
Although thousands of Blaschka glass models were made and shipped around the world, only about 60 (mostly small) collections exist. The largest assemblage is the Ware Collection of Glass Flowers at Harvard University. Most remaining models have sustained some structural damage—glass deterioration, delamination of glass layers and their separation from support structures, fading colors, and breakdown of organic materials. Many are in desperate need of conservation. Unfortunately, the various media used to construct the models make conservation difficult. Blaschka models are composites not only of glass, but also wire armatures, animal glue, paper, watercolor and oil paints, variously colored glass enamels for coloring and texturing effects, and often other unusual materials needed to achieve the desired realistic appearance. Further complicating conservation efforts, the Blaschkas never shared their formulas or techniques, which evolved and changed over their thirty years of model making.