Caution, paint dissolves.

Once I wanted to dive into the Macro world I've been looking for intermediate rings and here found it. The technical function is also given the Sing Nale of the lens to be passed through cleanly. But yesterday I had at one time at a Macro recording a very large black spot in the white image area. Nahdem I always cautious change my lenses and my EOS 6D is only a few weeks old, I was busy with the root cause analysis. It was a small black foreign objects on the image sensor. I could gently removed with a blower. But what was supposed to be got there I could because my caution when changing lenses not explain. Then I made me to look for my cheapest equipment which I screw on the Canon which are these intermediate rings. And lo and behold: Taking a sheet of white paper and knocks an intermediate ring fixed flat on the table crumbles it formally out of the rings, a lot of little, I guess paint particles. And one of them has probably lost on my sensor. Who has the part already should do the test with the Paipier times. Who wants to buy the part should be aware!