When a completely new network is created (from the File Menu) Recog allows one to specify the resolution of the new grid. In order to choose the resolution one must consider two parameters: what amount of detail is desired, and what aspect ratio is desired.
Detail
If one is planning on recognizing a small number of quite distinct characters (such as A, E, I, O and U), the amount of detail need isn't great. However if the characters are similar (such as a, e, i, o and u) one would need more detail to pick up the differences. The more pixels in the grid, the finer the details that the nets can extract, but the more learning it will require to train them.
Aspect Ratio
Numbers and capital letters are about 1.5 times taller than they are wide. Therefore to get the best results, a grid that is specifically designed for such letters should have a similar height to width ratio (4x6, 6x9 or 8x12 depending on the detail needed). Other characters have one to one aspect ratios (such as arrows pointing in different directions, or polygons).