Re: [Gimp-user] Printing a poster file issues

[Steve Kinney <admin pilobilus net>]

On 01/10/2017 05:19 PM, big__dav wrote:
> Please go easy on me as I have not done anything like this before and I am sure
> I am making a stupid mistake somewhere.
>
> I need to create a poster that is roughly 1.3m x 2m and the printer requires at
> least 300 DPI.

That a lot of pixels.  But I am confident that the PDF file size can be
reduced.

Try exporting your image to PNG, and to JPG format at about 85% quality.
 This should yield smaller files.  PNG is a lossless format, so there
will be no loss of resolution; JPG will be smaller than the PNG, at the
cost of a slight amount of noise.  The slight loss of resolution found
in the JPG file will not matter, if your poster will be viewed from more
than arm's length away.

You may also find that 150 DPI is sufficient for your purpose, again if
the poster will not be viewed at "normal reading distance," which gives
a file 1/4 the size of one in the same format at 300 DPI.

To make the PDF file, I would import the JPG into Inkscape, adjust the
and export to PDF from there.  Do File > Import and select the Embed
option.  Then do File > Document Properties, and select the resize page
to content option (set any necessary margins here).  Do File > Save As,
and select Portable Document Format.  In the dialog, set the resolution
to match whatever your image DPI is (i.e., 300 or 150 depending on the
image file you exported from the GIMP).

Your PDF files should be about the same size as the PNG and JPG files
you made with the GIMP.  A poster the size you describe will usually be
viewed from far enough away that 300 DPI vs. 150 DPI will not make a
visible difference, and if so, that gives you a 75% savings in file size.

Inkscape:  https://inkscape.org/en/

Generally speaking, Inkscape is "the" Free tool for making PDF files.

:o)