Sometimes when producing markers on the MK8, MK9 and the SP1 machine you can get a vertical unprinted line in the marker text. This appears when the machine cuts and stops feeding the profile.  

The reason why the unprinted line appears is that the needles in the thermo transfer head cools off when the machine is cutting. When the machine starts feeding the profile again, the needles doesn’t have the right temperature to transfer the ribbon onto the profile.

Solution:

The only way to get the unprinted line to disappear is to increase or decrease the length on the marker. When the machine stops to cut the marker the actually printing position is between two characters. The needles then have time to warm up before they should print the next character. You can also get the same result if you increase the space between the characters. All machines can’t adjust character space.