Crash-Course: swop densities / pdf

I am new to final prepress and could really use a quick explanation, if possible.

A client has requested that our pdfs have a max swop density of 280 or so. I just don't know how to make this happen, or frankly even what a really good explanation of swop density is.

If somebody could let me know how to create pdfs that adhere to that specification, i would be most appreciative.

[jackmik]

the pdf has nothing to do with the max density. the max density will be set in the native applications you are using, i.e. photoshop, illustrator, quark, indesign.

[Bart]

The SWOP Density is the amount of ink coverage allowed in any one area of a print file.

Say you are using a 4 colour black of 100%C, 100%M, 100%Y & 100%K. You would have an ink density of 400% in all the areas that use this colour. This can create problems where there is too much build up in ink on the paper and it can start to offset on to other parts of the sheet.

You can determine if your file exceeds 280% by using a preflight application like PitStop or FlightCheck. Changing the colour specs for solid areas is usually not a problem. Reducing the occurance in an image is not so easy and can require specialist skills/applications.

SWOP stands for 'Specifications for Web Offset Publications'.

Hope that helps!

[cari]

also have a look at all the icc's developed by the European Colour Initiative. www.eci.org

Overall I feel some are a bit heavy on the yellow, and high in total ink limit for West Australian printing conditions...

we use GCR light/85/230 30% dg for newsprint
UCR 90/320 20%dg for generic offset (coated/matte)

default Photoshop settings tend to be a bit heavy in black in the highlights, so upon conversion pull out a little bit of black from the black channel...

I'm testing the ECI iccs with some clients at the moment...

Thanks for the input!

In response to the comments, then, if i have 4 designers, is it enough to make sure that their photoshop is using say the swop v2 for all images? or do i still need to run finished pdfs through flightcheck or pitstop? Does anybody have a preference of which to use?

Again, i apologize for im ignorance in these areas! Thanks for the help!