I have an MG 3650s canon printer and it has started to print vertical lines that are sort of zig-zag. I have done both the automatic (no change) and manual head alignment, a little better but not perfect yet . The slight offset of print is enough for the Post Office to fail to read the QR/Bar Codes it prints out. Do I need to keep doing a manual alignment until all is ok or is there something else to try ? Thanks Brian.