What's the best way to make a pdf book cover for Create Space?

Question

I downloaded a paper back book cover template from Create Space and loaded it up into Inkscape (and used GIMP to crop the background images to fit the template).

What steps should I take, and what settings should I use, to guarantee the final pdf file of the book cover will test out at 300 dots per inch in Adobe Acrobat XI preflight?

1. Scenario One. Your background image jpegs have a resolution of 300 x 300 pixels.
2. Scenario Two. Your background image jpegs have a resolution of 72 x 72 pixels.

Answer 1

The image dimensions are how you calculate what size they need to be placed into your Inkscape file to keep a 300dpi PDF.

For the 300px file, it would need to be placed in your PDF at 1" square (300px/inch).

The 72 pixel one would have to be placed in your PDF at approximately .25" square (4 x 72 = roughly 300).

You could, of course, scale them larger in your Inkscape file, but the larger you go, the less pixels-per-inch you'll have when you print (increasing the likelihood of it becoming pixelated).