I try to border my bands in this way:
But I have a text field of my row detail with property isStretchWithOverflow="true"
In this way when I try to print my report, on the rows with overflowed text field, I've a discontinue on my border (white space instead draw line of frame).

Very simple.
I've added this property
stretchType="RelativeToTallestObject"on my frame object.So the line has not discontinuity.