> We are running 175/L using eliptical composed dot from
a Creo trendsetter, but the screening information is
coming from a 1-bit tiff work flow out of a Xitron
Rip. On our cyan, mag, and black seps we are getting a
dot frequency of 183 lpi while on our yellow we are
getting a 201 lpi.>
You could try changing the angle of your yellow …to 60
degrees for example. Harlequin precision screening (the likely culprit of you
200lpi yellow) will only optimize separations at certain angles (15, 75, 0,
45). At 60 you should get much closer to actual 175 lpi, and thus, less gain on
press…as long as its not your ink ;-). We have a similar workflow (Xitron/Trendsetter)
and screen the yellow sep at 175lpi/60 (Euclidean) to smooth up fleshtones.
Actual lpi on plate is 177-180 and gains are nested nicely with other seps. Whatever
you do, don’t turn off HPS entirely though…moiré city.
_______________
Michael Eddington
North American Color, Inc.
www.nac-mi.com