[scribus] 600 dpi

[Gregory Pittman]

On 06/07/2011 10:34 AM, John Jason Jordan wrote:
> On Tue, 07 Jun 2011 09:24:58 -0400
> Gregory Pittman<gregp_ky at yahoo.com>  dijo:
>
>> On 06/07/2011 09:03 AM, Tom Connolly wrote:
>>> Someone recently posted he has his tiffs at 600 dpi. AFAIK, no
>>> printer needs--indeed can use--more than 300 dpi. At 600 all you're
>>> doing is making a bigger file, with no benefits of sharper images.
>>
>> I think this  is a bit of a distortion. For _most_ purposes, 300dpi
>> should be adequate.
>>
>> For high-resolution printing commercially, 600 or even greater may be
>> desired. I'm not sure that once you get to 1200+ that it gets so easy
>> to see further improvement in the visible quality, unless you're
>> talking about printing to a very large format.
>
> I'm in a rush at the moment, but perhaps this would be a good time for
> someone to explain the difference and relationships (formulas) for DPI
> vs. linescreen. Also problems of dot gain with certain types of papers
> on press. How much DPI you need is a complex issue.

DPI and PPI only have any sense related to some output device, like a 
printer for the former, and monitor for the latter. I know some image 
formats can save at some DPI/PPI, but by default Scribus seems to bring 
in images at 72 PPI, and in the end what you have is some number of 
datapoints per horizontal line of the image, and a certain number of 
horizontal lines in the image what comes out in the output device has to 
do with some mathematical creation.
Obviously for an image where the output to PDF will be 300 or more DPI, 
what you see on screen even at best is pretty coarse unless you look at 
the PDF under high zoom.

Greg