A: First check whether the internal and external carbon is reversed.

Raise the printing temperature, you can try to print the pressure in the bar printer is too small;

The carbon belt itself is abnormal, with white spots, white strips and other abnormalities;

Ribbon does not match the label, such as printing coated or rough paper with a resin base;

The ribbon type and printer type do not match;

The print head or rubber roller shaft is dirty;

Uneven printing label printing materials;

Code editing software or printer attribute interface "concentration" or "blackness" adjustment;

Appropriate adjustment of the printer pressure, Note: industrial machines have a special adjustment of pressure devices, desktop some have some not;

Check if there is a mismatch between the ribbon and the label, such as resin-based printing on copperplate or rough paper;

Clean the printhead and rubber roller roller with an alcohol cotton;

Replace with a blank label to rule out the ribbon issue.