Check blade holder for any damages and make sure holder is clean inside.
Set the blade straight in holder. Check so there is no waviness in blade.
When bolts/screws are used for tightening of blade holder, tighten from center and out crosswise.
Use as low blade pressure as possible.
The top of the 45˚ back-up blade cut must not reach the end-point of the cylinder when the doctor blade oscillates. It should stop approximately 10 mm from the cylinder end. Only the doctor blade should pass over this area.