it depends on the batting. some batts need to be quilted every 2-4" if that is what you are using you need to quilt your borders. if you are using warm & natural then you can have up to 10" apart...but that does mean there should be quilting every 10"...so if your border is 80" long at least 8 places (every 10") needs to at least have a line of quilting....
the quilting needs to be in all directions, as close as the batting dictates.