C1S cover stock and gas ghosting

[cnjprinter]

We are a poster printer and have recently changed paper. We previously ran a dull ctd cover (C2S). We now run a dull ctd C1S. We have noticed that after the run the image looks "hazy or foggy" just not as sharp. Flat. The top sheet on the pile looks a lot nicer than sheets in the pile. The top sheet looks as good as the old paper did.

We have 2 sf presses. The one still runs the old C2S (this is a much larger press) and the other press runs the new C1S stock. When the larger press runs the old sheet things look as good as they always have.

The reason we changed to C1S is for the paper cost reduction.

Could this be a result of gas ghosting on the C1S? The gasses not being allowed out with this stock?

Has anyone else ever experienced this before?

Any comments are welcomed.

 

[jlind]

Re: C1S cover stock and gas ghosting

Hey Central:
A gas ghost will creat an image of some element of the signature, usually the top side ghosts on the bottom side of the sheet above. Soooooo, since this is C1S, are you printing just one side? How many colors? Any funky PMS colors? Any coatings? Willing to mail a sample? I've been there recently, so I feel your pain. This might be something else.
John Lind
Cranberry Township, PA
724-776-4718

 

[cnjprinter]

Re: C1S cover stock and gas ghosting

It is only printed on one side. I have seen gas ghosting before where you can see an image of the underside image, etc... But we only print one side for art posters here. It looks ALOT like the haze you see from gas ghosting...

4C process, sequence kcmy. Lightfast m,y.

I am wondering if the gasses release less on a C1S due to the underside being a rougher more course texture. Either trapping the gas or not being as smooth a finish to release. If we come in the next day the top sheet looks good. If we go down only about a half inch it is hazy, flat, waxy in appearance. It is this way on the entire skid. Whereas on the larger press all the sheets look good. Remember this larger press prints on a dull CTD C2S.

Thanks for your input would appreciate anything else...

 

[jlind]

Re: C1S cover stock and gas ghosting

Central:
Top sheet looks good. As you go down in the lift, the images look fuzzy/blurry. Is same ink used on both presses? If you take one of these blurry sheets and let air get to it, does the blurry look go away? Maybe over a few hours?
I think this might be a phenomenon that the inkies call synresis, if the blur goes away. It is thought to be caused by ink oils blooming to the surface. Given enough air, they will evaporate and the image almost returns to normal. I know, what do you do with a whole lift of this stuff? Run it through the press again, to wind it. Turn the air bars on high. Get a very low VOC (ink oil) ink. Is this a dark color you are seeing this in?
Just thinking out loud here. Let me know if it goes away with air exposure.
John Lind
Cranberry Township, PA
724-776-4718

 

[Indexx Printing]

Try K&E F1 Drive process ink and Flint Starbase PMS. We have had excellent results with this combo. They are both high gloss inks and have low vocs. Sometimes to slow down the drying a little we will double dose with Tegra reducing Jelly. Watch your stack temp. To me any thing Over 100 degrees F is too much. And don't run Hot air with a non aqueous coating job.

Todd