Italian design meets Dutch design in this optical illusion object. This unique glass object consists of a bowl with a yellow fine spiral and a white wide spiral. The three smaller glass bowls with yellow filigree are stacked into the bowl for spectacular optical effects. Copier intended a moire or interference pattern. It was exhibited in Gemeentemuseum Arnhem in 1986 and documented in the catalogue. On his 80th Andries Dirk Copier (1901-1991), who had been successful as glass designer since the early 1920s, began an international adventure as an independent artist. He traveled across Europe and to the United States to work with the best foreign glassblowers. With Lino Tagliapietra (1934) in Murano, there was magic, culminating in their 'Filigrane Interferenti'. After two working trips to Murano, Copier returns in the autumn of 1984. At the end of this visit, he and Tagliapietra carry out some additional experiments. Copier is completely taken by the effect of optical interference, also known as moiré. Copier works out his ideas for spectacular new work, which will eventually lead to Filigrane Interferenti, a series of groundbreaking one-offs with fascinating optical illusions such as this item.