Prismes vases, with their perfect grooves, are particularly complex to produce : each vase is hand finished and passed through a mill which cuts the grooves under a jet of water. In the case of the oval version, since it is impossible to create a perfectly straight line by hand without a guide, the grooves are pre-created in a steel mould then milled and then finally polished. Vase in mouth-blown glass : transparent and Smoke colored.