The printing device prints an image by forming {TAIL ~ dots} on the medium by {HEAD ~ the printing head} 
The printing device prints an image by forming { TAIL ~ dots } on the medium by { HEAD ~ the printing head }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD