Originally Posted by valex
I have been a long time k2pdfopt user via its integration with KindlePDFViewer. Now I have a pdf file with very wide margins which I want to print on a standard letter-size paper (8.5in by 11in) but without the margins and in "2 pages per sheet" mode. I need the reflow feature since the font comes out a little small even after the margins are cropped. Which options should I be using? Since I am printing on paper I need high dpi. I tried to use the dimensions of half of the letter-size page with the highest dpi k2pdfopt allows (-p 10-20 -w 5.5in -h 8.5in -odpi 538) but the output pdf has way too small font size and no reflow.
Because you are specifying the width and height in inches rather than pixels, you cannot use higher values of -odpi to magnify the text. That only works when you specify the width and height in pixels. Use the -ds (document scale) option instead, to trick k2pdfopt into thinking your source document is larger than it is, e.g. -ds 2.0
(with your other settings above) will magnify the text by a factor of 2, but if you use a value like -ds 2, you can probably reduce your output dpi to 300 for perfectly fine printable resolution and also set -idpi 300 so that the input dpi will match your output dpi (normally the input dpi is set to twice the output dpi, but that's overkill for what you're doing here). Higher values for the dpi will slow down the processing and make your output file unnecessarily large.