Alvarez calls the project Yves Kiln – a play on words that references both the ceramic firing process and the blue colour, which was first mixed by French artist Yves Klein in the 1960s.
The pieces are made by pushing clay through a three-tonne ceramic press that Alvarez constructed himself, called The Extruder. Like paint being squeezed out of a tube, the clay takes on a different shape depending on how it is pressed.
"Extrusion is not really an innovation in ceramics, it's something that's been going on for a while," Alvarez told Dezeen. "But I've made a machine that's a bit more upscale from the standard versions."
"I designed it to be automatic, so it can be controlled with a remote rather than using my own force," he said.
The machine is connected to a table that can be moved during the extrusion process, allowing the user to create different patterns, shapes and overlaps in the clay. The speed can also be adjusted.
This makes it possible to create forms with different textures and sizes – so some of the vases are spiky, while others have soft flutes.
All 12 vases match the tone of International Klein Blue (IKB), but Alvarez said this wasn't planned from the outset.
"In ceramic you have to choose whatever works well in terms of technical aspects," he said. "The blue that came out was very vibrant and beautiful, and it also happened to work well technically in terms of the firing process."
According to the designer, the blue is not fully mixed with the clay but is also not a glaze. He describes it as "a separate clay that is spread over the top of the pieces, almost like a paint".
"For me, ceramics has a bit of magic in the material, and you can't really control it. But once you find the right recipe, and the right firing technique, you can achieve a consistency," he said.
"I wanted it to look like the pieces themselves were made of this solid blue material," he added.
"I wanted it to appear like these objects had come straight out of the extruding machine, with not much process being put into it afterwards, when in reality they have been painted with this material over the top."
The 12 pieces were created for an exhibition called Unsighted, held in the 5VIE district for Milan design week.
Eight international designers were asked to produce a work without knowing what the setting would be. The space given to Alvarez was decorated with beige striped wallpaper and old wooden flooring – a striking contrast to the hue of his design.
"In the brief, all it said was that it would be in a palazzo in Milan, which is one of the reasons why I wanted to make these taller pieces," he said.
"The pieces can be used as vessels, but they are very tall so I guess they're kind of impractical as vessels," he added. "Rather than being seen as a vessel, they can also be seen as fragments of architecture, like a column or a pillar."
Milan design week 2018 took place from 17 to 22 April 2018. Other highlights from 5VIE included a collection of vegan furniture made from different plants and minerals.