FM Screening Help!

[Fmoser]

Hi all,

I have been given the daunting task of trying to implement FM screening for a Japanese Newspaper printer.

I have never been involved with FM screening before. So I am looking for some advice on the processes involved for implementing FM.

Any info will be very much appreciated!

Cheers
Brenden

[Jezza]

Hi Brendan, just done a quick google and found these

http://www.seyboldreports.com/Specials/FMscreen/fm.html

http://www.ipasystems.co.uk/pages/ABS.htm

Hope it helps

[Rickyp_uk]

Let us know how you get on using it on web work. We used it at my last place for sheetfed. We were getting som really nice results, but the machine minders used to moan like buggery cos they had to lay right back on the ink coverage.

[PantherMac]

You can try contacting RIT. I know some of the professors, and they definitely ran FM trials on their Sunday2000, so can probably provide you w/ some numbers. I'd imagine tight color control and curve's, would be about all that's needed. It's really not that much harder to print 20-micron FM, than 175 LPI if you can hold your highlights.

- Mac

[rhctp]

I used Creo's FM screening in my last shop on web presses and it worked well once all of the pressman were used to it.

[Jalan]

We us FM screening on a fairly regular basis. The press used is a 2 color sheetfed. We use a rather large compensation via the calibration curve as it causes a lot of dot gain. We use 31um for the dot size and it's a fairly close comparison to 200 lpi.
The FM screening is controlled by our Nexus Rip by Artwork systems.

Hope this helps.

[bluzbird]

we used it as a demo and it made the shadows lighter on some things, but it also made colors gain more than the good ole fashioned dot. If your presses are fairly new it ought to work alright, one good point is we ran 2400/133 and it takes alot logner to image...stochasic imaged really fast like we were running 1200/100...it definately takes better press equipment to run with it ....IMHO.
Matt

[Fmoser]

Hi All,

Thanks very much for your feedback its great to read comments from people in the real world of prepress. You have all raised some good points which will help me greatly.

The plan is to use LucidDreams Itone software to do the sreening. The newspaper is interested in both FM and Hybrid screening options, which Itone does well. Itone uses Agfa's CrystalRaster screening.

From what I've read process control and building the right linear is a big part of getting things right. Can anyone offer advice on the process of building an accurate linear?

Thanks again.

Cheers
Brenden

[David]

Making FM (stochastic) linear is a little tough. Your average run-of-the-mill densitometer can't read it. So you don't know what a 50% dot is, or where it is, or how much gain you're getting.
We use Techkon Digital Microscope DMS Pro that runs on a PC to read ours.

[mtnman]

An alternative to a straight stocastic screening would be to use a hybrid like Agfa's Sublima. We love it, we're running 210 line on both of our webs. It looks and acts like conventional except in the hi-lite and shadow areas. There it uses a stocastic like random pattern but doesn't actually print under 3% just drops out a precentage of the dots randomly to simulate 2 and 1%. We've never printed so much detail and we're still able to run great saturation.

David