C'est ce que je comprends à l'issue d'une recherche rapide sur Google, soit pour une impression sur verre (lien 1), soit pour une impression 3D (lien 2) qui chacun peuvent nécessiter un traitement thermique... dans un fourneau.

Lien 1 >> "Digital glass printing works the same as digital paper printing: An image is sent to the printer, which then gets transferred into the glass. /.../ after the printing, the glass must be dried, and then tempered in a furnace."

Lien 2 >> "A Sintering Furnace Solution for 3D Printing
/.../ the 3d printed parts still require careful thermal sintering and/or heat treatment to help them achieve proper size, hardness and density.
/.../ Selecting a Furnace for finishing your parts is largely a function of what kinds of metals your will process (temperature), what kind of atmosphere you will heat them in, (air, hydrogen, nitrogen), and what kind of throughput you need in your production or lab environment."