Grid Size for A4

While square pieces of papers are widely used in origami, A4 paper is probably the most widely used paper around daily life.  Why don't we use A4 paper to play around and fold some casual origami work?

For box pleat, we can at least try with the below grid size.  I use 17x24 the most.

Grid Size	Error as a Square
12 x 17	0.17%	multiplies: 24 x 34, 36 x 51, 48 x 68
17 x 24	0.18%	multiplies: 34 x 48
29 x 41	0.03%
41 x 58	0.02%
46 x 65	0.09%

* suitable for any A series of paper.  (i.e. A1, A2, A3, A4...)