Hi Michael,

Ok I see. Yet I can say that I had experienced it before (one time I had a STL file and it was not water tight but the printing machine was able to print it! However, I have to say I did not discover the mistake until the piece was printed. I think I got lucky!) So, as u mentioned I think it depends on the situation and I can say it is safe to have the 3D model water tight.

Thank you for your support.