Update: In the Projects area, you will find more information relating to this message. Tools: A digital micrometer, a thin print removal tool. Both of these tools can be purchased online at Amazon.com removal tool -> https://www.amazon.com/ToyBuilder-Labs-Print-Removal-Tool/dp/B00VB1U886/ref=sr_1_15?crid=1RZQP45OLO2EL&keywords=spatula+for+3d+printer&qid=1551292394&s=gateway&sprefix=spatula+for+3D,aps,144&sr=8-15 micrometer -> https://www.amazon.com/Neiko-01407A...al+micrometer&qid=1551299407&s=gateway&sr=8-4 The print bed can be out of level / tilted even after doing the leveling procedure. The difference will be very small and only show up when printing large objects. The type of tilting is where one edge is lower than the other and can be either left / right or front / back. Front to back tilting can show up as a filament line where one end is thinner than the other end of the same filament line. Using a digital micrometer, this article will detail how to extra-fine tune the bed leveling. STEP1) Print the two lines of filament using the Fine Tune Z-Offset wizard. Tap the Options icon and tap the Clear the bed option. After the print bed lowers, carefully remove one line of filament. Using the digital micrometer, measure the thickness of the filament line in three places (start, middle, and end). Record the readings. To get the average reading ->> in a calculator, add the three measurements together and divide the total by 3. Record the average. STEP2) Carefully remove the other filament line and measure it in 3 places. Record those measurements and calculate the average. Subtract the smaller average from the larger average. The three images below are start, middle & end measurements. As you can see from the images, the center of my print bed is slightly elevated with respect to the 4 posts at each corner of the print bed. Start: Middle: End: For a precisely leveled bed, the difference between the two averages should be less than 0.05 mm (or 50 microns) As detailed in the procedure, shim the lower side to bring it closer to the higher side. You are trying to reduce the difference between the height of the two lines of filament. EXAMPLE: While measuring the line filaments during the leveling procedure for my print bed: First Pass: Left: 0.32 mm; Right: 0.41 mm for a difference of 0.09 mm Second pass: Left: 0.30 mm; Right: 0.37 mm for a difference of 0.07 mm Third Pass: Left: 0.23 mm; Right: 0.21 mm for a difference of 0.02 mm In each case, I made sure the print bed was cleared and clean before restarting the Fine Tune Z-Offset wizard. < STEP3) in the procedure> Once you have the shimming completed, continue with the adjustment section. Happy Printing!