It's information overload: you either think in pixels (pixel elements, helllllooooo?!) or in some real dimensions like cm or inches AND the density of the dots within such distance (dpi, dots per inch, but in some countries also dots per centimeter,...)

The reality is that in the end it's all about the dots. You can only see the dots that are there. So it's all about pixels really. cuz you paint pixels, Once you have so many you can slap a fictitions dpi value on it but it won';t mean a thing until some software or driver or printer decides to use it along with that other parameter: the real work dimesion.

real-worl-dims x dpi = total dots, aka pixels

Seriously, do you think there's anything different in a file, I mean in the file, just because you change from 72dpi or 100 dpi to 300 dpi? I mean just changing that piece of header info. Nope it doesn't touch the pixels. You still have 8000 of them if you started with 8000 of them. But what you're now saying is that you'd like 300 of them packed into each inch, not just 72. So, the image will span across a shorter distance cuz you'll have exhausted the available 8000 pixels (or dots) in a shorter distance when you pack 300 per inch vs. when you pack only 100 or 72 of them per each and every inch.

 Well, that's my thinking. I never work in two dimensions when a single dimension does the exact same thing: I mean why worry about dpi AND inches when in the end you get the resulting number of dots in the form of pixels. It's all about pixels.

You can load a 3000 pixel wide image into Irfanview and change the DPI setting from 100 to 300 dpi and save it. That won't prevent you however from changing it back to the original, or printing it at different dimensions, smaller or larger in dimensions on paper. Yu can always have it resample on-the-fly to match the desired dimensions on paper.

Well, theoretically anyway. Unfortunately some software thinks that you really care to drop 2/3 of the pxiels when changing the dpi from 300 down to 72.

 Internally, it's still all about pixels though.

oh well, but that's just me.

Quote - The old rule of thumb about DPI used to be higher DPI Better print output. 

Now if you buy a Digital Camera, the output is usualy at 2048 x 2048 @ 72 DPI.  So if going buy the old rule of thumb that High DPI is better, that would mean the digital photos shold come out crappy but they dont when printed.

Also a lot of artists here work on Resolutions of 5000 to 10000 Pixels for high printer output.

This old timer needs to be updated.  It took me a long time to drill into my head, that Screen Resolution and DPI Resolution were two sepreate things.

What is throwing me off is new Digital Cameras that produce 72 DPI pictures but at higer screen resolutions.