How to impose 1 Bit Tiff files

[helmuttgutenberg]

I would like to impose 1 Bit Tiff files to get a print in offset in a same sheet with different dot (fm,Am dot in a same signature)

[Marko]

I would like to impose 1 Bit Tiff files to get a print in offset in a same sheet with different dot (fm,Am dot in a same signature)

the main purpose of a 1 bit tif is that its already screened with a set of dots, line screen and resolution.

Do you have something to do your screening. If so, try a pdf or contone tiff.

mark

[pcmodem]

If your RIP software has the ability to create a Low-Res link FPO file of your 1-bit tiff. You should be able to create an impo from your FPO files, then send the impo back to the RIP to link back up with the High-Res files.

[imagesetting]

We used to have a customer who used something called Iceworks (I need to check that) - it did exactly what you wanted - ie it created a 1 bit tiff, screened, FM or conventional.
We would output film for him from his files he'd set up.

The RIP wouldn't screen his files as it treated it like line work.
So you would be able to lay up your files imposed with different screen types on the same signature.

[gordo]

We used to have a customer who used something called Iceworks[SNIP]

I believe that you are thinking of IceFields: ICEFIELDS

To the OP.
Many RIPs have the ability to export 1 bit screened tiffs of your documents which can then be imposed just like any other file using your imposition application or placed and imposed in a page layout application and exported as a PDF.

Your RIP may have this ability as a licensed option. If this is a one-time test then your vendor may give you a temporary trial license (usually 30 days) so that you can do your testing.

Kodak's Prinergy has a utility called "DotShop" which allows you to apply different screening to different areas of a PDF prior to RIPping. Perhaps other workflows also have this ability.

A word of caution, mixing different screening types (especially FM and AM) on the same press form can be problematic because they have different ink/water requirements. If you must mix them then you should try and impose the press form so that halftone screens of the same kind are inline with one another.

best, gordo

[Al Ferrari]

A word of caution, mixing different screening types (especially FM and AM) on the same press form can be problematic because they have different ink/water requirements. If you must mix them then you should try and impose the press form so that halftone screens of the same kind are inline with one another.

best, gordo

Hi Gordon,

Other areas of a plate such as a large screen area in line with a large solid also have different ink/water requirement. Yet these are handled routinely. Why do the different ink/water requirements of AM/FM areas of the plate behave specially differently?

Please explain at greater length.

Thanks,

Al

[gordo]

Other areas of a plate such as a large screen area in line with a large solid also have different ink/water requirement. Yet these are handled routinely. Why do the different ink/water requirements of AM/FM areas of the plate behave specially differently?

I'm not so sure that a large screen area in line with a large solid has a different ink/water requirement.

Basically, all things being equal, for any given tone value, the dots of an AM/XM screen have smaller perimeter to area ratios as well as carry a thicker and less even film of ink than typical FM screens. In contrast, FM screens have a larger perimeter to area ratio and carry a thinner more homogeneous film of ink. That makes the FM screen susceptible to over emulsification or attack by the fountain solution if the ink/water balance on press is set up to print AM/XM.
That's not to say there will be problems running AM/XM on press with FM - but there may be, and it may be sufficient to invalidate a comparative test (if that's being done in this case).

best, gordo

[imagesetting]

Ahh yes, IceFields it was.

I would second the mixing of screen types on the same job (if possible), would introduce complications for the press minder.
You maybe able to print something, but how acceptable the results would be is down to you and your customer to establish.
http://www.imagesetting.com

[Al Ferrari]

After sleeping on this, I am starting to understand the potential problem suggested by Gordon.

This could be tested with a plate form consisting of a row of 10 - 90% AM screen test patches across the plate followed a row of aligned 10 - 90% FM screen test patches, followed by a solid bar.

How would a given pair of AM/FM patches compare when an even density was achieved across the plate for the solid bar? This form could be used for testing different ink and fountain solution formulations.

Perhaps there is a published report of some such test that someone could point us to.

Al

[gordo]

After sleeping on this, I am starting to understand the potential problem suggested by Gordon.[SNIP]
Perhaps there is a published report of some such test that someone could point us to.

Al

The difference in lithographic performance was written about in the article "The Lithographic Impact of Microdot Halftone Screening" published by the Technical Association of the Graphic Arts in the 2003 TAGA Proceedings.

It's also alluded to or mentioned in most technical documents about screening.

Unfortunately there's very little published technical information, or proper research done, on such basic subjects as ink/water balance, solid ink density,grey balance etc. There's a great deal of opinion, anecdotal experience, and parroting of so-called industry truths, but.....oooops! I'm starting to rant.....sorry!

best, gordo