Glass casting process

Anna Alsina Bardagí in the studio

I create my sculptures through kiln casting, a process in which glass is melted in a mold and slowly cooled to form the final piece. This technique allows me to achieve detailed forms within the glass while maintaining the optical clarity that is central to my work.

See the 7 steps involved in casting a glass sculpture →

Each optical glass sculpture is unique and takes several months to complete, passing through multiple stages of casting, firing, grinding, and polishing.

After developing the concept and making the mold, the glass is fired at 850°C in a kiln for around two weeks. The firing follows a 14-stage cooling process, with very slow cooling rates that allow the glass to anneal properly.

Once firing is complete, I begin the polishing process. Each sculpture goes through several stages of grinding and polishing, often taking weeks to reach optical transparency.

My sculptures are made using OHARA eco-optical glass. Produced in Japan, its purity and transparency allow me to work with light as an integral part of each piece.

The process in pictures

Making the prototype

Preparing the plaster mix

Building the walls to pour the plaster mix

Optical glass blocks prior to melting in the kiln

Mold ready to be fired in the kiln

Glass inside kiln

Sculpture after firing and prior to polishing

Glass after casting

Grinding a glass sculpture with silicon carbide

polishing optical glass

Polishing a glass sculpture with cerium oxide