Unfortunately, I realized that the magnets from contaminating the paper, and sometimes quite significantly. In addition yet that is the strength deficient. 1-2 leaves holding a magnet without any problems. But since indeed up to 7 sheets was given, I've tried it out with 7 simple leaves. It turned out that the whole is always slipping down because the magnet is not strong enough. Even with 2 magnets keep the whole unsure. Tried it on different surfaces, unfortunately without much success. Therefore, the magnets go back unfortunately.