[Gimp-user] Sizes of an image - display v printing

[chuckie <forums gimpusers com>]

> When you look at your picture at 100% in Gimp, Paint and other
> applications, it is displayed "dot for dot", one pixel of the picture
> is
> one pixel on your screen, and therefore it is displayed using your
> screen definition (so given the size you report we can assume that the
> resolution of your display is 828/(23/2.54)=91 pixels/inch).
>
> On the other hand your picture has an embedded "print definition"
> which
> is used for printing, in your case 828/(3.5/2.54)=600 pixels/inch.
> This
> sets a theoretical size for the picture, size at which the picture is
> printed (as long as everything in the print stack abides to it).
>
> Print definition (in Pixels/inch), print size (in inches) and size (in
> pixels) are related by the formula:
>
> print size = print definition * pixels
>
> Note that this means that you can only pick two of these values, the
> third is determined by the first two.
>
> In Gimp you can un-tick "View>Dot for dot", in which case the picture
> will be shown at the print size, if your screen resolution is properly
> set (see Edit>Preferences>Interface>Display).
>
> When you create the image, you should set the size in pixels big
> enough
> so that you can print it at the required size with a print definition
> of
> at least 200 pixels/inch (photo) preferably 300 or more if there is
> text/logos or other computer-generated graphics. The advanced options
> in
> "File>New..." let you enter a print size and print definition, and
> compute the required size in pixels.

Reducing the DPI from 600 to 200 made a big difference for dragging the image
into an email. Thank you.

-- 
chuckie (via www.gimpusers.com/forums)