Howto level the bed?

In order to level the bed I use a simple sheet of paper that I put on the bed. Before starting any other thing, I heat up the extruder to 195°C and the bed to 60°C. In fact, with the heat it is "inflating" itself a bit, which can be 1mm sometimes.

1. Next I make the extruder go to the (0,0,0) positition (home all). I manually adjust the bed using the screw next to the origin. I adjust the bed in a way that it it possible to move the paper more or less hardly between the nozzel.
2. After having moved down the table for 1mm, I do let move the head to the farest Y position (the table should move backwards if you sit in front of the printer). I make shure that the paper is still between the bed and the nozzle and then I command the printer to go to the Z=0 position (home Z). I adjust the scren on that side in the same way than on the oder side. Here it is important to do the adjustment in such a way that the applied force to make the paper move is the same as for the first point.
3. In the next step I increase the X position to it's maximum. Don't forget to pull down the table for at least 1mm before moving it! Using the same technique as before, I adjust the last screw under the bed.
4. Now it's thime to move to the last point, mich is around (X,Y) = (200,0). This last point is just a "control point". The force applied to move the paper should be the same here as on the previous three points. If this is not the case, please restart at step 1. Generally it is true to say that if the force applied to move the paper is greater than the one in step #3, the screw from step #1 is not tied enough.

The use of a sheet of paper has another advantage: the bed stays clean from any drops coming out of the nozzle (remember, the heater is on).