[Scribus] Registration marks

[Louis Desjardins]

>Am Freitag, 24. Juni 2005 10:49 schrieb Tobias Hilbricht:
>>  Dear readers of this list,
>>
>>  how do you produce registration marks for four-colour printing with
>>  Scribus? That is crosses consisting of 100 % C, M, Y, K each helping to
>  > place the four separations exactly?

[snip]

>Sorry for bothering you

Don't be sorry! This gives me the occasion to add some info on 
registration marks and other press marks. :)

The following may or may not apply to your specific project.

Registration marks are not an absolute necessity at this stage of the workflow.

Registration marks are not needed when:

1. The document will be printed on a digital printer (ie. where the 
operator has no control on the way the machine actually does the 
registration, this all being done in the color engine itself). Unless 
you need to control the actual preciseness of the machine.

2. The document will be electronically imposed and then printed on an 
offset press.

For #2, the printer will most likely use a dedicated imposition 
software that will allow to place a variety of press marks, including 
sophisticated color bars. All these will help not only register the 
images from the various plates to combine a complete image out of the 
press, but also help control other variables, such as ink density, 
dot gain, etc. These color bars are often developped by the press 
manufacturer itself. The color bars and the registration marks 
generated by the DTP app at output is, in this case, of no use at all 
and the imposition program will discard this information because it 
is not needed on press.

Registration marks however are important if you're going to print on 
an offset press without any kind of imposition. That is, single page 
document, printed one up. A large poster being a good example of 
this. Even then, your printer will most likely want specific marks 
and color bar the DTP app cannot provide and will use the imposition 
program anyway.

In the time where imposition was done manually or mechanically, all 
these marks were of upmost importance: the eye of the technician or 
the "eye" of the machine needed something to look after. Digital 
imposition have changed that.

If your printer still does imposition manually (many small shops 
still do that), then yes, you need registration marks. Also, although 
being very unlikely nowadays, you need those marks when making an 
analog color proof by hand, without the help of punch holes.

The printer is the better person to help you determine for sure what 
is needed in terms of registration marks.

HTH

Louis

>
>Yours sincerely
>
>Tobias Hilbricht