Originally Posted by

**Hai-Etlik**
Yes, it does matter. At the equator, the "box" bounded by a small equal angles of latitude and longitude is approximately a euclidean square. As you move into higher latitudes, it narrows and becomes more like a trapezoid, until you get a very narrow triangle at the poles.

A map in a projection suitable to a restricted extent is going to try to minimize distortion within that extent so those shapes will be approximately preserved: At mid latitudes, a lat-long box with equal angles would be approximately a rectangle with an aspect ratio determined by the latitude. In a normal cylindrical projection it will be projected as precisely a rectangle.

In tangent normal equidistant cylindrical, all such boxes are squares, but this means that they, and all other shapes, are being stretched out east-west. Which is a rather noticeable form of distortion. So my point stands, to get a square lat-long graticule, you can either be covering a small area near the equator in a projection that minimizes distortion within your extent. Or you can be in Plate Carree, in which case you can be anywhere, but would have significant and ugly distortion *unless* you are covering a small area near the equator.