boro vs soft glass

[lindag]

My DH is thinking he may want to melt glass. He's tried it and seems to have an aptitude for sculptural work. I've got plenty of boro I haven't used lately so I thought I'd get him started on that. I was explaining it all to him and then he asked a question I couldn't answer. What makes boro hard vs soft glass? I know the working differences, I know coes, but what is the difference?

[Firebrand Beads]

I think it has to do with the recipe and the amount of silica involved. Soda lime glass is made from primarily soda, lime, and silica (and coloring agents, etc etc etc...) while boro is made from primarily silica and boron oxide. And coloring agents, etc etc!

[lindag]

Thanks, it makes sense. DH will be happy to hear it.