Recommended resolution (dpi) for \includeimage pics (pdflatex)

I designed a newsletter using a logo and a topbanner, 2 pages. It is to be send by mail (A4-paper) and by e-mail (pdf). As usual, I used 300dpi for my graphics.

The result is 1.2M in size, which is on the limit for some recipients. Is 300dpi too much? Is there a certein resolution pdflatex uses to scale an image to let's say 5cm? Any experiences, what resolution is good for both, on screen reading and printout? (Home laserprinter)

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Take the size of your monitor in inches and your current resolution, perhaps 1600x1200 on a 21" monitor? That’s roughly 127 dpi horizontally. 1024x786 on 19" is roughly 90dpi. So if you supply more “dots” per inch they have to be reduced by the programming used for displaying the pdf.

For printing however this is not enough. It gets even more complicated when colors are involved.

However with pdfs you don't have to use raster graphics. If the logo is available in a vector format it might be considerable smaller and still look good on screen and print as well.

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unfortunately vector is (at least now) not an option, but maybe I can get one in the future. – Nikodemus Dec 10 '11 at 16:07

I normally use 600 dpi and 1200 dpi. If you are not concerned about posting your pdf for downloading--that may give you issues with large sizes--rather go for a high resolution. The reason for this, is that if one magnifies the page the image does not suffer.

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Just as a side note: There is a not very well known option for \includegraphics provided by pdflatex: interpolate which enables interpolation for raster images (if the PDF viewer supports it), so that you don't see pixels if you zoom. – Martin Scharrer Dec 9 '11 at 15:28
@MartinScharrer Thanks Martin. This works nicely with Adobe Reader, but not with any Poppler based viewers. – Yiannis Lazarides Dec 9 '11 at 16:02
It's a PDF feature, so the PDF viewer must support it. You can't do anything about it, if a particular viewer doesn't do it, except of posting a feature request of course. – Martin Scharrer Dec 9 '11 at 16:36