I've read up a bunch of posts about the differences and understand about misregistration, etc. I also realize it will probably vary somewhat depending on the actual printing equipment, ink, and paper types... but in "general" when people suggest not using rich blacks for small/thin lines can someone shed some light on actual numeric measurements to take the "relativity" out of the words "small" and "thin"? I.e. some people consider 8 point font "small" where others consider 12-14pt "small". I realize fonts can vary in weight so I am not expecting an answer in terms of font size, was just using font as an example of the relativity of the word s small and thin. I'd imagine it would be inches (or mm) but have no idea if it's 1/2" 1/4"? 1/8"? 1/16"?
For me.. type is never rich black. At least not body copy. Some headlines which are considerably larger (±30pt) then okay.
For anything else, less than 2pt is a mistake to apply a rich black to. An even 2pts is close. But this really depends upon how such a line is used. If it's in the middle of a piece of art then it doesn't really matter. If it's a simple rule on a page, then there's no need for rich black until the weight starts getting greater than 4pts.
Just my opinion though.
No one measures items on a page in inches. Perhaps the page dimensions, sure, not not items on the page. Millimeters and points are more standard for page items. Inches for page items would only even be used for large, oversized printing.
This is a fun question to answer...
It is like asking a pitcher on a baseball game what kind of curved throw you should make... I have no idea until I'm in front of the project!
I need to consider the quality of the printer I am working with.
I worked with one printer that had an awesome quality, the machine was a 4 head printer, was dammed expensive but very specialized one, it only printed paper somewhat bigger than a tabloid, and the registry was superb.
The company sent some of the magazines we worked together for some national award competition. I do not know if we won btw. Probably not.
And I worked once with some guys that had a well-known brand but the machine was big and old. The registry problems were about 1-1.5 mm on some parts of the sheet... It was a big problem.
I need to consider the real need for a rich black. You do NOT need rich black on thin lines or small text if it is the only text on a white background. Font size is not the only thing that defines it, the design is the one that defines it.
Does this black interact with other blacks? Does this black is big enough that needs extra punch? Does the design need rich black? What type of rich black?
Can you risk some misalignment? is this risk worth it? Is the usage of a dull black the real risk?
What is your relationship with the printer, can you trust them? Do they trust you, is the project in a hurry?
How many are you printing? what size, what is the relationship between small elements? What paper are you using...
Probably it reduces it to a series of proportions and relations between the final element vs the probable misalignment. Let's say you have a misalignment of 1/4 mm and your element is 1 mm. Probably that is ok if it is the yellow color the one with the problem, magenta will be probably bad.
Probably the design will accentuate this misalignment because it is used on a pattern of lines...
But you probably need to make a rich black passing the paper twice using the same black plate... Can you afford it? do you need it?
More and more questions come to my mind...
Never, Ever have I used a rich black on font/type.
I've only used it with letters that goes on billboards/OOH. But at that point I stop thinking about them as type and start as objects. It'happen, for me, around 180pt.
From a color-thinking way rich-black is used to have black color. Because black paint is not black. But it's only visible if you print a large (in relation to page itself and colors around) apla.
From personal experience - printing text with rich black is like titling your email to printer with "Please F**k up my print in the worst way possible"