User`s guide

MEDIA TIPS AND TRICKS

Media Sensitivity

Different media types exhibit different heat sensitivity. The

VARIABLE_DARKNESS command controls the amount of printhead heat.

Different media types can also exhibit different response times. The

media is in motion while the printhead dots are heating and cooling, so

areas of the label that theoretically should stay white are subjected to

temperatures close to their darkening temperature. This can result in

some bleeding of dark areas into light areas. This can adversely affect

the reliability of rotated bar codes. Increasing print speed and print

darkness tend to increase bleeding, so speed and darkness can interact

to affect the reliability of rotated bar codes.

Some Cognitive printers support the VARIABLE MEDIA_ADJUST

command, which can reduce print bleeding in some cases. Printers that

support this command employ an advanced "dot history" algorithm,

which tracks the activity of each printhead dot from one dot row to the

next. If a given dot was off prior to being commanded on, the printer will

apply a little extra energy to the dot to force it to come up to full

temperature faster, thus improving the contrast on the leading edges of

objects. This can significantly improve the reliability of rotated bar

codes.