Zebra Technologies R-140 - Manual (Page 85)

Adjustments
Toggle Positioning
Both toggles should be positioned so that they provide even pressure on the
media. The toggles are positioned by sliding them to the desired location.
On media too narrow to accommodate both toggles, position one toggle
over the center of the media and decrease the pressure on the unused toggle.
NOTE: Make sure that the toggle pressure is even across the width of the
media. Otherwise, the media and/or ribbon may “drift.”
76 Zebra R-140 User’s Guide
Figure 30