Is dot gain mainly for rasters ?

[CASIMIR17]

Hi there,
please excuse what might look like a stupid question to some but I'd like to know whether or not Dot Gain settings only apply to rasters.
This is something I can find in the Photoshop color settings but not in the Illustrator ones..
Could someone shed some light on this for me ?

Many thanks

[don Arnoldy]

whether or not Dot Gain settings only apply to rasters.Dot gain applies to all dots of ink put onto a piece of paper--even those dots that are shaped like letters. It is influenced by the viscosity of the ink, the absorbancy and texture of the paper, and other factors that modify the drying time of the ink.

It is most noticable in halftones, where it can cause color shifts. While photos are an obvious example of a halftone, screen tints are also halftones.

Vector-described illustrations are suseptable to the effects of dot gain to the extent they use screen tints and/or process-mix colors.

[CASIMIR17]

Thanks for the reply.
So how do you control dot gain if not within the application you create the object from ?
Is this embedded in the color profile you use ? but then again it doesn't leave much space for customization (I'm referring to my previous Photoshop and Illustrator example - Illustrator does not have that option in the color settings)

I'm using InDesign CS2 but I thought you managed the dot gain issues in the applications where you create your objects from.

Many thanks

PS: brilliant forum !

[don Arnoldy]

Thanks for the reply.
So how do you control dot gain if not within the application you create the object from ?You can't really control (or compensate for) the dot gain until you know what it is. Before you can know what kind of dot gain you're gonna have, you have to know the characteristics of the press and paper you're using.

Generally, you don't know these things when you are creating elements--many times an illustration or image will be used in many different print runs.

In the workflow with which I am most familiar, the dot gain compensation is done at the end of the process when the plates or negs are made--using a setting in the imagesetter called a "transfer function."

Photoshop uses dot gain values when one converts from RGB or L*a*b* to CMYK when it decides how much black ink to use (this is called "black generation") in the image.

Standard contemporary practice is to make the designer (or the layout person) responsible for converting the images to CMYK before they are placed in a document and delivered to the printer. Un fortunately, this is generally the person least-well-equipped to do the conversion properly. It really should be done just before output, by someone who is very familiar with the press/paper environment--the prepress guy.

[djb]

You can't really control (or compensate for) the dot gain until you know what it is. Before you can know what kind of dot gain you're gonna have, you have to know the characteristics of the press and paper you're using.

Generally, you don't know these things when you are creating elements--many times an illustration or image will be used in many different print runs.

In the workflow with which I am most familiar, the dot gain compensation is done at the end of the process when the plates or negs are made--using a setting in the imagesetter called a "transfer function."

Photoshop uses dot gain values when one converts from RGB or L*a*b* to CMYK when it decides how much black ink to use (this is called "black generation") in the image.

Standard contemporary practice is to make the designer (or the layout person) responsible for converting the images to CMYK before they are placed in a document and delivered to the printer. Un fortunately, this is generally the person least-well-equipped to do the conversion properly. It really should be done just before output, by someone who is very familiar with the press/paper environment--the prepress guy.

What Don said.