147 
media sensor An electronic device equipped with photosensors to detect media and the top of 
form on die-cut, notched or reflective media. 
 
MMPS (millimeters per second) Metric measurement of printer speeds. 
 
notched stock Media, typically tag stock, with holes or notches in the material that is used to 
signal the top of form. The printer must be set to ‘gap’ to use this media type. 
 
preprinted media Label stock that contains borders, text, or graphics, floodcoating, etc. 
 
perforation Small cuts extending through the backing and/or label material to facilitate their 
separation. Also referred to as “perf”. 
 
print speed The speed at which the media moves under the printhead during the printing 
process. 
 
reflective media Media imprinted with carbon-based black marks on the underside of the 
material, which is used to signal the top of form when the ‘reflective’ sensor is enabled. 
 
registration Repeatable top to bottom alignment of printed labels. 
 
reverse speed The backward rate of media motion into the printer during tear-off, peel and 
present and cutting operations for positioning the label at the start of print position. 
 
ribbon An extruded polyester tape with several layers of material, one of which is ink-like, 
used to produce an image on the label. Also referred to as “foil”. 
 
ribbon wrinkle An undesirable overlapping of the ribbon during the printing process that leads 
to voids on the printed label, typically caused by an improper printhead leveling cam 
adjustment. 
 
roll media A form of media that is wound upon a cardboard core. 
 
start of print The position on the label where the printing actually begins. 
 
tag stock A heavy paper or synthetic printing material, typically featuring a notch or black 
mark for TOF and no adhesive backing. 
 
thermal transfer The printing method that creates an image by transferring ink from a ribbon 
onto the media using the heat from the thermal printhead. 
 
TOF (top of form) The start of a new label as indicated by a label gap, notch, mark or 
programming. 
 
void An undesirable blank space in a printed image.