I want my documents to be able to be printed on A4 (210×297 mm) as well on Letter (8.5×11 inches) paper. (The "documents" are TIFF files with raster text on them. This is important to me. Being in Europe, I can send such a file to my friend in US, and he would be able to print it on Letter instead of A4, without any troubles.) Does it mean that the safe size of the image is 558×756 points (7.75×10.5 inches, 2325×3150 px at 300 dots/pixels per inch), or there is an error somewhere?
A4: 210 x 297 mm => a little less than 595 x 841 pt I like to reduce 595 to 594, because 594 is exactly 8.25 inches Letter: 8.5 x 11 inches => 612 x 792 pt So, A4 x Letter = 594 x 792 pt And then we need to subtract about 0.25 inches, that is, 18 points on each side for non-printable margins, which gives 558 x 756 pt (7.75 x 10.5 inches), which is 2325 x 3150 px at 300 dots/pixels per inch.