I'd like to draw a square grid - 40x25

Thanks!

Effects -> Render -> Grid

how do i control the number of squares in the grid ( 40 x 25 ). i see i can control everything else except this.

The grid is drawn over the bounding box of the selected object. So if your horizontal and vertical spacing is going to be 10, draw a 400×250 rectangle, select it, and add the grid.

OK that'll work - thank you!