+OVERVIEW OF TARGET USAGE:
+
+By cropping with -c and studying the results, define the areas of the input PDF's pages you want visible. Then, with--nup4, map those areas onto 4 input pages per 1 output page, arranged in such a way that double-sided print-out of those output pages can be cut, folded, and bound (helped by addition of stencils for small incisions to carry rubber bands or the like) into a small A6 book. Each unit of 8 pages from the input PDF is mapped by --nup4 onto two pages representing two sides of a (no-tumble-duplex-printed) A4 paper:
+
+ +-------=-------+ __________________
+ (front) (back) | 4 | 1 = 2 | 3 | 4 /=|===|============
++-------=-------+ ==> +-------=-------+ ===> _/|\_ v >=|===|============
+| 4 | 1 = 2 | 3 | / | \_ \=|===|============
+|-------=-------| +-------=-------+ 1-> | 2 | 3 | | \ / <- cut out!
+| 8 | 5 = 6 | 7 | ==> | 8 | 5 = 6 | 7 | | _/ \_ | | \ |
++-------=-------+ +-------=-------+ |/ \| | \| (p. 5)
+
+To turn this paper into a small 8-pages book, first cut it into two A5 papers along its horizontal middle. Fold both A5's by their vertical middles, with pages 2-3 and 7-6 on the folds' insides. You now have two 4-page A6 "books" of pages 1-4 and pages 5-8. Fold both closed and (counter-intuitively) stack the second one on top of the first one (creating a temporary page order of 5,6,7,8,1,2,3,4). This reveals a small stencil on the top left of page 5 – cut it out, with all other pages folded and aligned under it, creating a small notch in the upper "inner" corner of all pages. Turn around the stack to find a mirror stencil on the bottom and repeat the cutting. Each page now has cuts on top and bottom of its inner margins into which a rubber band can be hooked, or through which a string may be looped and tied, to bind the page's inner margins into a kind of book spine. You may now swap the order of the 4-page books back into a proper final page order (of 1,2,3,4,5,6,7,8) and repeat the whole process for each further --nup4 output paper.
+
+COMMAND EXAMPLES: