Trouble with ppi

[BoredPanda]

Hey everyone! I need to create a A3 image with 150 ppi but every time I try to change the size, it changes the ppi and whenever I try to change ppi it changes the size. Can you give the exact steps to follow? I'm going crazy here

[rich2005]

(12-22-2018, 05:46 PM)BoredPanda Wrote: Hey everyone! I need to create a A3 image with 150 ppi but every time I try to change the size, it changes the ppi and whenever I try to change ppi it changes the size. Can you give the exact steps to follow? I'm going crazy here

1. First Gimp works in pixels and A3 is a real world paper size in millimetres.

However, let Gimp do the arithmetic for you There is a preset A3 canvas File -> New -> Template (1)

   

but, it is @ 300 ppi (2) (the size is 3508 x 4960 px) Set the resolution to 150 ppi (3) (size 1754x 2480 px) and that canvas is all set up for printing at A3.
That might be all that is needed. 

2. If you have some image that you need to fit on a canvas that size then:

   

This image is 2752x4890 @ 180 ppi (4) Larger than my required canvas and wrong ppi

Using Image -> Scale Image the height and ppi can be set (5) and the image scaled.

It is now too narrow for A3 so resize the canvas Image -> Canvas Size Make sure the width/height link is broken, set the correct width, center, set whatever fill needed and resize.

   

easy