FM Screening and duotones

[Prepper]

We are getting ready to test FM and just wondered if it works well with duotones, standard ones with K and a spot ink used?

Also if you know of any special cases\images\instances that FM doesn't work ok vs. AM. Spot gradients, etc?

Thanks

 

[Magnus]

Hi prepper!

We are using Fuji Taffeta FM-screen 20-30μ. When we first tested the screen the technicians from Fuji tried to set the curves in the rip so that the printed FM screen matched with our AM-screen (ISO). But it didn't work at all.. But after investing in some icc-profiling gear and software that could do good device-link conversions we got some really great results! Proofing Fogra39 (ISO) and printing Fogra39 on both AM and FM-screening.

We haven't got any problems with graduations/shadings etc, but when we print on rough uncoated papers we sometimes get some grainy effects on "vectorgraphics". Seems like the FM-screening brings out the paper structure more some how..

 

[gordo]

We are using Fuji Taffeta FM-screen 20-30μ. When we first tested the screen the technicians from Fuji tried to set the curves in the rip so that the printed FM screen matched with our AM-screen (ISO). But it didn't work at all.. But after investing in some icc-profiling gear and software that could do good device-link conversions we got some really great results! Proofing Fogra39 (ISO) and printing Fogra39 on both AM and FM-screening.

We haven't got any problems with graduations/shadings etc, but when we print on rough uncoated papers we sometimes get some grainy effects on "vectorgraphics". Seems like the FM-screening brings out the paper structure more some how..

Bizarre. There should be no problem building plate curves that align your FM tones to your AM tones on press. It is a simple thing to do. The hue of one and two color screen tint builds will not look the same due to FM's larger gamut. The FM may appear lighter/brighter due to its increased chroma - but measured tonality should match. Perhaps it is the color difference that you are correcting for with a device link profile?

Because FM screening is a high frequency/resolution screen it can make the paper texture more visible. The same thing will happen if you run an AM/XM screen at a similar lpi.

best, gordon p

 

[gordo]

We are getting ready to test FM and just wondered if it works well with duotones, standard ones with K and a spot ink used?

Also if you know of any special cases\images\instances that FM doesn't work ok vs. AM. Spot gradients, etc?

Thanks

Yes, FM works well with duotones and gradients.

What you need to be aware of is that spot color inks, like Pantone, are not usually formulated to be wet trapped (over printed) - even though printers do that all the time - and that can result in a mottled appearance which may get blamed on the screening when it's actually an ink problem. Also, the pigment grind of the ink may not make the ink suitable for halftone screening. Pigment grind disperses the ink particles - the finer the grind the more evenly dispersed to ink particles. The more evenly the pigment particles are dispersed the smoother the ink appears in solids and on halftone dots.

Here's a close up of the Cyan process printer that shows good ink transfer and good pigment grind - AM/XM on the left, FM on the right:

Here's a close up of the Orange spot color printer that shows poor ink transfer and poor pigment grind - AM/XM on the left, FM on the right:

You can see the clumping and non uniformity of the spot color ink which can cause mottling, grainy flat tints, and erratic dot gain/tone reproduction.

When you order your inks, make sure that your ink formulator knows that you intend to screen the color and wet trap the ink.


best, gordon p

 

[Prepper]

FM and Duotones

FM and Duotones

Thanks, that sounds like it may work for our vignetted PMS covers then. But we have one 1/4" bar of 15% tint of the PMS spot ink that runs across 4-color images, how does FM handle a 5th color added in like that? Our covers are KCMY plus 1 spot. We run the 15% spot tint at the same angle as the K and that works well.

Never worked with FM yet (about to though) so how does it handle a 5th color? No screen angle to set so how do you output a 5th color?

Terry

 

[gordo]

There's no screen angle but there is a different pattern for each color.
Depending on your workflow, spot colors may just cycle through your process color patterns, I.e. the 5th spot may use the K pattern, the 6th spot may use the C pattern etc.
Or, there may be dedicated patterns for spot colors for you to choose from.

If not then choose the pattern of the screen that is least prominent in the 4/C, I.e. if the 4/C is a blue then use the Y or K pattern.

What you're trying to avoid is printing one color with the same pattern and tones as the one it's overprinting. If you do, you may see what appears to be a mottle pattern. It's not a big issue with FM screens, so if you can't use the best pattern don't worry about it as it's not likely to cause an issue.

best, gordon p

 

[rich apollo]

Prepper,
The printing shouldn't be a problem. You may have some issues matching previously printed materials because a 15% FM screen is not equivalent to a 15% AM screen. As was discussed in this thread AM and FM screens that match in tone value will yield results that look different - both in density and hue.

The good news is that you only face that problem once. Then the FM screened piece becomes your new standard.

 

[Arshad]

problems in fm screening

problems in fm screening

we just tried 15 mic fm screen on our brand new heidelberger, well running the job i found that that half tone ( skin tone) it get patchy i mean we feel that print is not upto the standards, as if too much water is running on the job , we generally run hybrid screening ,
please advice.

 

[gordo]

we just tried 15 mic fm screen on our brand new heidelberger, well running the job i found that that half tone ( skin tone) it get patchy i mean we feel that print is not upto the standards, as if too much water is running on the job , we generally run hybrid screening ,
please advice.

Hybrid screening is basically AM screening.

Maybe you're running too much water, maybe you haven't done your curves properly, maybe....

A press does not know what a skin tone is.

There can be many reasons why screen tint builds look patchy with an FM screen but don't with an AM (or hybrid AM - same thing) screen.

Why did you try FM? Why did you try "15" micron?

BTW, Whose FM screening did you try? What does your vendor say?

best, gordon p

 

[sachin]

Hi,

Does anyone has comparision between Spekta and FM/Highbrid screening. We are using Harlequin 240+ LPI Highbrid (HXM) screening, but expected results yet not achieved. We use HDS (Medium) Screenning for FM. But skin tones are not very smooth.

Any advise

Hybrid screening is basically AM screening.

Maybe you're running too much water, maybe you haven't done your curves properly, maybe....

A press does not know what a skin tone is.

There can be many reasons why screen tint builds look patchy with an FM screen but don't with an AM (or hybrid AM - same thing) screen.

Why did you try FM? Why did you try "15" micron?

BTW, Whose FM screening did you try? What does your vendor say?

best, gordon p

 

[gordo]

Does anyone has comparision between Spekta and FM/Highbrid screening. We are using Harlequin 240+ LPI Highbrid (HXM) screening, but expected results yet not achieved. We use HDS (Medium) Screenning for FM. But skin tones are not very smooth.

Any advise

As I wrote before - a press does not know anything about skin tones. It simply lays down a film of ink.

What were the results that you expected but didn't achieve.

Harlequin 240 LPI Highbrid (HXM) screening is basically 240 lpi conventional AM screening (except for extreme highlights and shadow tones which wouldn't impact skin tones). Were you successful with 240 lpi AM? What tones in the skin tones are not smooth. How are you doing your RGB to CMYK conversions? Is your ink laydown correct? Is ink transfer optimal? Are your plates and CtP qualified for this screening? etc. etc.

AFAIK HDS Medium is an "18 micron" FM screen. Have you tried HDS Coarse instead (~20 micron FM and equivalent to Spekta 400/500)?

best, gordon p