Overwhelmed by options?
Click on the links below
to learn more about:

Good question. It probably depends upon where you live, as much as what you're working on. People in North America use Letter size paper (8 1/2 x 11 inches). Place two of these side-by-side, and you get Tabloid (11 x 17 inches).

The rest of the world uses ISO 216 sizes. A4 is a little larger than Letter (210 x 297 mm). Place two of these side-by-side, and you get A3 (297 x 420 mm).

Letter size	Tabloid size
A4 size	A3 size

All of these are available in both page orientations: landscape, where the largest dimension is horizontal, and portrait, where the largest dimension is vertical. Why does this make a difference? The triangles are arranged so that the main axis is always vertical. Thus, your desired page orientation may depend upon what triangle orientation you want.