To create the FRGP webpage header using Gimp, I started it and did
a File->New.... I set the Width to 535 pixels
because that's what Linda Lester said was the ideal size for
most browsers. I set the height to 100. I set the
Image Type to Grayscale. I set
the Fill Type to White.
Then in the main dialog box labelled The Gimp I selected the Pencil (4th one down on the left). Then on the dialog box labelled Brush Selection I chose the smallest dot (5th one over on the top). Then in the drawing window I was able to draw lines from a specific point A to another specific point B by clicking the mouse at point A and releasing, then holding down the shift key, moving to point B and clicking the mouse. This is a tedious way to draw, but allows coordinate-based drawing.
To zoom in, move the mouse over the drawing and hold-down the right mouse button. Pull-down to View->Zoom In.