I am having an LCD with a resolution of 640x480. What is the relevance of pixel per inch for an image to be used for developing a GUI in this LCD? This image is not going to be used in any other LCD's with different resolution. According to me , this option is irrelevant as actual pixels per inch is constant in the LCD .
But I found that in GIMP we need to give this option to create an image. What value should I give for my image ?