Last Updated: Jul 19, 2016 Views: 123
Thank you very much for your inquiry. Molds for pressing machines are generally made from cast iron. Many glass factories such as Blenko, Imperial and Fenton used cast iron molds. Here's a link that may be helpful to you.http://www.glassblower.info/glassblowing-molds/press-mold-glassblowing.html
If production is low a more inexpensive way of pressing the glass by hand would be to us a graphite mold such as this: http://www.craftster.org/Craft-Supplies/General-and-Miscellaneous-Crafting-Supplies/Mosaic-and-Glass-Crafts/Spiral-Flower-Graphite-Push-Mold/222403/
If you have any further questions feel free to contact me.