I've made several collages and wanting to print an 8 x 10 I'm constantly told "there will be a resolution" problem. I guess I'm ignorant of what happens when I reduce the "huge" jpg to a smaller size. I just assumed that the smaller the picture the more pixels - apparently NOT! How do I correct this? Thank you.
The smaller the picture is resampled, the fewer the pixels.
Image size is dimensioned in pixels. 24 megapixels might be 6000 x 4000 pixels (6000 x 4000 = 24 million). In uncompressed data, there are 3 bytes per pixel (the most common normal 24 bit color), but JPG compresses the file significantly smaller.
To print 8x10 inches at an optimum 300 pixels per inch is a size of
(8 inches x 300 dpi) x (10 inches x 300 dpi) = 2400x3000 pixels.
Fewer than that is less than optimum.
300 pixels per inch is optimum (more won't help color photo printing).
200 pixels per inch might be acceptable quality, but not best.
100 pixels per inch is considered too few pixels.