>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
