Vycor

First, a relatively soft alkali-borosilicate glass is melted and formed by typical glassworking techniques into the desired shape.

[citation needed] For some applications the final step is skipped, leaving the glass porous.

[citation needed] Vycor has an extremely low coefficient of thermal expansion, just one quarter that of Pyrex.

[citation needed] Corning manufactures Vycor products for high-temperature applications, such as evaporating dishes.

[citation needed] Porous vycor is a prototypical matrix material for the study of confined liquid physics.