cd 74 poster ghosting

[jmt]

have a prob running a poster .the poster has a cmyk image in the middle surrounded by a black and yellow screen with knocked out type and white picture frame around image.i have turned all forms to oscallating the rollers only a month old with good stripes good fountain solution still no luck. I was thinking of trying to get pre press to make the job crooked so its running at a angle i have heard this before but never done it myself. any help is appreicated

 

[NotAGooner]

Yes, running at an angle is what we used to do, if that is not possible, run take up bars that are outside of the trim area, you may have to run it on a bigger sheet though?

 

[mrheidelberg]

CD 74 if set up correctly should not ghost ..... Inking rollers and damper settings should be re-checked

 

[NotAGooner]

It's a picture frame, not normal ghosting, I've never seen any press even larger size presses than a 72 that can eradicate that kind of ghosting no matter how well the roller settings are, the suggestions I made are perfectly valid and have been tried and tested by many pressmen as well as myself.

 

[jmt]

i agree with notagooner the press prints great just this one job has given us problems.i have had other jobs with ghosting and turning the oscallating rollers on always help the prob. how much should i get them to move the image. a couple of millimeters or half a inch?

 

[turbotom1052]

if youve tried everything else and can't get rid of ghost, cocking job will definitely do the trick but it will make finishing a bit more difficult. . They will need to make a first cut with the backguage cocked more than the cutter will accommodate by means of a simple adjustment. Id recommend printing the job cocked at least a half inch. If your scanning color bars for closed loop color control you will need to image the plates with the color bars parallel to the sheet edge. Before doing all that id make sure youve done everything on press to eliminate ghost. If you're running alcohol you may want to try to eliminate it or at the very least get it down to minimum. Id also look to fully integrate the alcolor and take off vario if equipped. Good luck and let us know how it all turned out.

 

[jaed]

Is the problem with the boarders being lighter/darker on the tops and sides? If this is the problem you can do what National Geographic used to do with the cover of their magazines', they ran a cut back screen along the top and bottom of the yellow boarder so it would match the sides. I don't know how much difference was built in but it might be something to try.

good luck.

 

[FSA]

jmt
Many times i have come in for my shift to find that the operators before me can't do the job and are fuming mad at the press. I've seen ghosts in dark green be the worst. If your running alcoholit is your first downfall, turn the predampening down so it starts off with a touch of scuming. Were the ghost lines are you need to have the roller blowers on. And most important that a fresh water form and inkers are in the unit(s) that is giving you the headach, with the last form only 2mm to the plate for it is a smoother only. Having rollers on hand is a must if a shop wants to do quality work, when the job is done you can leave them in or change them back pending on the age of what you pulled out.
FSA

 

[jmt]

thanks all for the tips . Running the job at a angle worked for us no ghosting at all.customer was very happy . We lost money on the job but now we know when we see something like that to angle it.

 

[mrheidelberg]

Bet that was fun to trim on the guillotine !!

 

[jmt]

was very easy just have to make the first cut