> This article's brief explanation of how the process works seems somewhat misleading, as it claims that the ion substitution creates tension in the glass, whic

> This article's brief explanation of how the process works seems somewhat misleading, as it claims that the ion substitution creates tension in the glass, which makes it harder for cracks to spread - but cracks propagate under tension. The article uses “tension” informally, meaning under mechanical stress. I would not read too much into that. But yes, you are right. > I am wondering if the chemical process is slow, which might be another reason for it not being adopted for ordinary objects such as drinking glasses. The fact that such glasses tend to fail catastrophically and shatter in small shards is a problem, for something that is used in homes, often with children, and that is bound to break at some point. Not great from a safety perspective.