I have two good inksticks that fractured into several pieces while sitting quietly stored in a drawer in my climate-controlled house since I bought them a few years ago. There was no physical trauma involved, they just spontaneously split into pieces. I imagine this may be due to the very dry climate where I live. The fractures were clean, though there were several in each stick. There were four or five horizontal fractures, and some of the sections were split a second time vertically. I used this glue about a week ago, following the instructions and using strong rubber bands to hold together each new glue joint for several hours. So it took me a few steps to assemble an entire ink stick. In the last few days I have used the sticks and they are fine so far. I try not to unduly stress them, but grind ink with about the same pressure as usual. The bottom (grinding) surface of one repaired inkstick is crossed by one of the glue joints, and I cannot see any difference at all in the ink it makes. Since it is identical to the main stick I've used for the past 2 years I think I would be able to tell the difference. Overall this is a great product that has saved two rather expensive ink sticks for me.