Antique glass engraving

Hi! Has anybody engraved antique glass bottles ? I have some cobolt blue and some brown small medicine bottles but was not sure if there could possibly be any concerns with engraving them. Anybody know anything about this? Thank you!


In general glass is a very stable material. Liberating the cobalt from cobalt glass would take a lot more energy than your laser is going to impart.

Speculating, but I think the biggest risk would be silicon dust, like any glass. if you laser it too hard you can perhaps cause glass dust to flake off the engrave. I haven’t seen anyone try to quantify the risk on that but my gut says it’s low. you need really fine dust being thrown around your workspace to get into your lungs, like saw blades ripping up granite etc. I doubt lasering releases fine enough particles in anything close to dangerous concentrations.

I guess what I am saying is that I doubt it’s any worse than standard glass. I think the only glass that would give me pause is uranium glass. I doubt it would present much risk either, but it’s one of those cases with potentially large consequences, so small risks matter.

But yeah I am speculating on all of this. I do think I’m right that you don’t need to worry about toxicity from the cobalt, if that’s what’s worrying you.


Thank you!

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Cobalt is the strongest colorant known so the amount will be insignificant, however the danger of lead is much greater. Your average cheap blue glass like in commercial medicine bottles will be the same soda-lime glass that makes up most of what is made. However, glass of great value is often made with a lot of lead, and that can be a lot worse than old-timey car exhaust.
If the bottle seems slightly heavier than it should be and more decorative than usual I would set it aside.

In trying to confirm details it is totally amazing how much misinformation is out there. In general antique glass dealers have barely a clue as to what causes different colors, and even when the factory was operating , they were historically more secretive than most. But the dealer cannot appear ignorant to the customer so explanations that are commonplace and all the dealers agree are often total bs. As a result, when looking stuff up this “wisdom” permeates what Google can find.